Cambridge International Examinations Cambridge Ordinary Level

Transcription

1 Cambridge International Examinations Cambridge Ordinary Level * * COMPUTER SCIENCE 2210/12 Paper 1 Theory October/November hour 45 minutes Candidates answer on the Question Paper. No Additional Materials are required. No calculators allowed. READ THESE INSTRUCTIONS FIRST Write your Centre number, candidate number and name in the spaces at the top of this page. Write in dark blue or black pen. You may use an HB pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, glue or correction fluid. DO NOT WRITE IN ANY BARCODES. Answer all questions. No marks will be awarded for using brand names of software packages or hardware. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. The maximum number of marks is 75. This document consists of 12 printed pages. DC (AL) [Turn over

2 1 (a) Give two reasons why a programmer would choose to write code in a low-level language [2] (b) High-level languages require either an interpreter or a compiler to translate the program. The table below lists a number of statements about language translators. Tick (3) to show which statements refer to interpreters and which refer to compilers. Statements Interpreter (3) Compiler (3) Translates the source code into machine code all at once Produces an executable file in machine code Executes a high-level language program one instruction at a time Once translated, the translator does not need to be present for the program to run An executable file is produced [5] 2 State four functions of an operating system [4] 2210/12/O/N/16

3 3 3 (a) Explain what is meant by: (i) Serial data transmission [2] (ii) Parallel data transmission [2] (b) A computer in a factory is connected to a printer. The printer is located in an office 1 km away from the factory. Identify which data transmission method would be most suitable for this connection. Give two reasons for your choice [3] 2210/12/O/N/16 [Turn over

4 4 4 Nine bytes of data are transmitted from one computer to another. Even parity is used. An additional parity byte is also sent. The ten bytes arrive at the destination computer as follows: parity bit bit 2 bit 3 bit 4 bit 5 bit 6 bit 7 bit 8 byte byte byte byte byte byte byte byte byte parity byte One of the bits was corrupted during the data transmission. (a) Circle the corrupt bit in the corrupt byte in the table above. [1] (b) Explain how the corrupted bit was found....[2] 2210/12/O/N/16

5 5 5 A computer uses an 8-bit register. The 8-bit register contains binary integers. (a) Write the denary (base 10) value represented by: [1] (b) All the bits in the register are shifted one place to the right as shown below Write the denary number that is represented after this shift....[1] (c) State the effect the shift to the right had on the original denary number from part (a)....[1] (d) The original number in part (a) is shifted three places to the right. (i) Show the new binary number: [1] (ii) Write the equivalent denary number....[1] 2210/12/O/N/16 [Turn over

6 6 (e) Describe the problems that could be caused if the original binary number in part (a) is shifted five places to the right....[2] 6 Four computer terms and eight descriptions are shown below. Draw lines to connect each computer term to the correct description(s). Computer term Description Data can be read but not altered Arithmetic and logic unit (ALU) Carries out operations such as addition and multiplication Stores bootstrap loader and BIOS Control unit Fetches each instruction in turn Random access memory (RAM) Carries out operations such as AND, OR, NOT Stores part of the operating system currently in use Read only memory (ROM) Stores data currently in use Manages execution of each instruction [4] 2210/12/O/N/16

7 7 7 (a) Complete the truth tables and name the single logic gate that could replace each logic circuit: (i) A B X A B 0 0 Working space X Single logic gate...[3] (ii) A A B Working space X X 0 0 B Single logic gate...[3] 2210/12/O/N/16 [Turn over

8 8 (b) (i) Draw a logic circuit to represent the following logic statement: X = 1 if (A = 1 AND B = 1) OR ( (B = NOT 1) AND C = 1) A B X C [4] (ii) Complete the truth table for the logic statement in part (b)(i). A B C Working space X [4] 2210/12/O/N/16

9 9 8 Identify whether the four statements about file compression are correct by writing TRUE or FALSE in the following table. Statement TRUE or FALSE MIDI files store the actual music notes in a compressed format JPEG files are examples of lossless file compression MP3 files are, on average, 90% smaller than the music files stored on a CD MP4 files are examples of lossy file compression [4] 9 (a) Explain what is meant by a denial of service attack....[2] (b) Name and describe two other potential security threats when using the Internet. Security threat 1... Description... Security threat 2... Description... [4] 2210/12/O/N/16 [Turn over

10 10 10 (a) Describe what is meant by HTML....[3] (b) The following URL is typed in: This URL is composed of three parts. State the part of this URL that is the: File name... Protocol... Web server name... [3] 2210/12/O/N/16

11 11 11 A security system is installed in a house. A hexadecimal number is entered to activate or deactivate the alarm. (a) The alarm code is set to hexadecimal number 2 A F Show how this number would be stored in a 12-bit binary register. (b) Identify two sensors that the security system could use to detect intruders. Describe how each sensor could be used in the security system. Sensor 1... Description... Sensor 2... Description... [6] [3] 2210/12/O/N/16 [Turn over

12 12 12 Explain the differences between freeware and free software [4] Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge International Examinations Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at after the live examination series. Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge. 2210/12/O/N/16

13 Cambridge International Examinations Cambridge Ordinary Level * * COMPUTER SCIENCE 2210/13 Paper 1 Theory October/November hour 45 minutes Candidates answer on the Question Paper. No Additional Materials are required. No calculators allowed. READ THESE INSTRUCTIONS FIRST Write your Centre number, candidate number and name in the spaces at the top of this page. Write in dark blue or black pen. You may use an HB pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, glue or correction fluid. DO NOT WRITE IN ANY BARCODES. Answer all questions. No marks will be awarded for using brand names of software packages or hardware. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. The maximum number of marks is 75. This document consists of 14 printed pages and 2 blank pages. DC (SLM) [Turn over

14 2 1 To process an instruction, a central processing unit (CPU) goes through a cycle that has three main stages. Name each stage in this cycle. Stage 1... Stage 2... Stage 3... [3] 2 Name each of the potential security issues described in the five statements below: Statement Security issue The act of gaining unauthorised access to a computer system... Program code that can replicate itself with the intention of deleting or corrupting files stored in a computer... A small file sent by a web server to a web browser; every time the user visits the website, data about user preferences is collected... The act of illegally changing the source code of a program so that it can be exploited for another use... Malicious code installed on a user s hard drive or a web server which redirects the user to a fake website without their knowledge... [5] 2210/13/O/N/16

15 3 Five computer terms and seven descriptions are shown below. Draw a line to connect each computer term to its correct description. 3 Computer term Description Serial, simplex data transmission Several bits of data sent down several wires, in both directions, but not at the same time Several bits of data sent down several wires, in both directions, at the same time Parallel, half-duplex data transmission An even or odd number of bits set to 1 in a byte, used to check if the byte has been transmitted correctly Parity check One bit sent at a time, over a single wire in one direction only Automatic repeat request (ARQ) An additional digit placed at the end of a number to check if the number has been entered correctly A value transmitted at the end of a block of data; it is calculated using the other elements in the data stream and is used to check for transmission errors Checksum An error detection method that uses response and time out when transmitting data; if a response is not sent back to the sender in an agreed amount of time, then the data is re-sent 2210/13/O/N/16 [5] [Turn over

16 4 4 The Henslows Diner is a local restaurant. (a) Staff currently use a keyboard to input a customer food order into a computer. The food order is then sent to the kitchen. State two disadvantages of using a keyboard to input a customer food order [2] (b) A concept keyboard has a flat surface that is overlaid with images of food items available from the restaurant menu. Staff can click on an image to add the food item to a customer food order. The Henslows Diner wants to change to a concept keyboard to input customer food orders. Explain two benefits of making this change [4] 2210/13/O/N/16

17 5 (c) The Henslows Diner stores personal data on a computer. This computer is connected to the Internet to allow the data to be backed up. There is currently one security method in place to protect the data on the computer from unauthorised access. This is a password. Give two other security methods that could be added to improve the security of the data. Describe how each method will keep the data safe. Security method 1... Description... Security method 2... Description... [4] 2210/13/O/N/16 [Turn over

18 6 5 Three switches, A, B and C, each send values of 0 or 1 to a logic circuit. Value X is output from the logic circuit. Switch A Switch B Switch C Logic circuit Output X Output X has a value of 1 depending on the following conditions: Switch A sends value 1 AND Switch B sends value 0 OR Switch B sends value 1 AND Switch C sends value 0 (a) Draw a logic circuit to represent the conditions above. A B X C [5] 2210/13/O/N/16

19 (b) Complete the truth table for the conditions given at the start of question 5. 7 A B C Working space X (c) A microprocessor regularly samples the output, X. Each sample value is stored in an 8-bit register as shown below. One bit of this register is reserved as a parity bit. Five consecutive output values of 1 indicate a fault condition. Identify which of the following registers shows a fault condition. Parity bit Register Y Register Z [4] Register...[1] 2210/13/O/N/16 [Turn over

20 8 (d) When eight bytes of data have been collected, they are transmitted to a computer 100 km away. Parity checks are carried out to identify if the data has been transmitted correctly. The system uses even parity and column 1 is the parity bit. The eight bytes of data are sent together with a ninth parity byte: parity bit column 2 column 3 column 4 column 5 column 6 column 7 column 8 byte byte byte byte byte byte byte byte parity byte (i) Identify which of the eight bytes contains an error. byte...[1] (ii) Identify which column contains an error. column...[1] (iii) The incorrect bit is indicated where the byte number and column cross. Give the corrected byte. [1] (iv) Calculate the denary value of the corrected byte [1] (v) Considering the fault condition given in part (c), explain why it is very important that the incorrect bit is located and corrected [2] 2210/13/O/N/16

21 6 High-level or low-level languages can be used when writing a computer program. 9 State two advantages of using a high-level language and two advantages of using a low-level language. High-level language advantage High-level language advantage Low-level language advantage Low-level language advantage [4] 7 Modern Liquid Crystal Display (LCD) monitors use Light-Emitting Diode (LED) backlit technology. Give four benefits of using LED technology [4] 2210/13/O/N/16 [Turn over

22 8 Four descriptions about compilers and interpreters are shown below. 10 Draw lines to indicate which descriptions refer to a compiler and which descriptions refer to an interpreter. Description It is more difficult to debug the code since one error can produce many other associated errors. The speed of execution of program loops is slower. Compiler It produces fast, executable code that runs directly on the processor. Interpreter It is easier to debug the code since an error is displayed as soon as it is found. [4] 2210/13/O/N/16

23 9 A security light is controlled by sensors and a microprocessor. 11 Describe how the sensors and microprocessor interact to switch on the security light when an intruder is detected [6] 2210/13/O/N/16 [Turn over

24 12 10 (a) A manufacturer of aeroplane engines assigns a denary identification number (ID) to each engine. One engine has the ID: 0431 (i) Convert this denary number to a 12-bit binary format. [2] (ii) Show how this number would be represented in hexadecimal [3] (b) The current status of the engine is sent to a computer in the aeroplane. Each piece of data collected is 8 bytes in size. Data collection occurs every 30 seconds. Calculate the number of kilobytes that would be needed to store the data collected during a 10-hour flight. Show your working.... kilobytes [3] 2210/13/O/N/16

25 13 (c) At the end of the flight, all of the data are sent to the aeroplane engine manufacturer using the Internet. The computer in the aeroplane has a MAC address and an IP address. State what is meant by these two terms. MAC address... IP address... [2] (d) When sending this data, security is very important. Data are sent over the Internet using Transport Layer Security (TLS) protocol. Name the two layers that make up TLS [2] 2210/13/O/N/16 [Turn over

26 14 11 Explain why ethics are important when using computers [6] 2210/13/O/N/16

27 15 BLANK PAGE 2210/13/O/N/16

28 16 BLANK PAGE Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge International Examinations Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at after the live examination series. Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge. 2210/13/O/N/16

29 Cambridge International Examinations Cambridge Ordinary Level * * COMPUTER SCIENCE 2210/22 Paper 2 Problem-solving and Programming October/November hour 45 minutes Candidates answer on the Question Paper. No Additional Materials are required. No calculators allowed. READ THESE INSTRUCTIONS FIRST Write your Centre number, candidate number and name in the spaces at the top of this page. Write in dark blue or black pen. You may use an HB pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, glue or correction fluid. DO NOT WRITE IN ANY BARCODES. Answer all questions. DO NOT ATTEMPT TASKS 1, 2 AND 3 in the pre-release material; these are for information only. You are advised to spend no more than 40 minutes on Section A (Question 1). No marks will be awarded for using brand names of software packages or hardware. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. The maximum number of marks is 50. This document consists of 11 printed pages and 1 blank page. DC (CW/FD) /1 R [Turn over

30 2 Section A You are advised to spend no longer than 40 minutes answering this section. Here is a copy of the pre-release material. DO NOT attempt Tasks 1, 2 and 3 now. Use the pre-release material and your experience from attempting the tasks before the examination to answer Question 1. Pre-release Material The manager of a supermarket needs a program to record donations to charity. Each customer has the choice of three charities to donate to, and 1% of their shopping bill will be donated to the chosen charity. Write and test a program for the manager. Your program must include appropriate prompts for the entry of data. Error messages and other output need to be set out clearly. All variables, constants and other identifiers must have meaningful names. You will need to complete these three tasks. Each task must be fully tested. TASK 1 Set up the donation system Set up a routine that allows: the names of three charities to be input and stored the charity names to be displayed with a number (1, 2 or 3) beside each name a choice of 1, 2 or 3 to be entered to choose the charity, all other entries rejected the value of a customer s shopping bill to be entered the donation to be calculated three totals to be set to zero ready to total each charity donation TASK 2 Record and total each donation For a customer s shopping bill: input a charity choice of 1, 2 or 3 input the value of a customer s shopping bill calculate the donation add the donation to the appropriate total Output the name of the charity and the amount donated. TASK 3 Show the totals so far Extend TASK 2 to accept: donations from more customers a charity choice of -1 to show the totals so far Display the charities names and the totals in descending order of totals. Calculate a grand total of all three totals. Output GRAND TOTAL DONATED TO CHARITY and the amount of the grand total. 2210/22/O/N/16

31 1 (a) All variables, constants and other identifiers should have meaningful names. 3 (i) For three of the variables that you have used in Task 1, state the name, type and its use. Variable 1 name... Type... Use... Variable 2 name... Type... Use... Variable 3 name... Type... Use... [3] (ii) Name and describe the data structure(s) that you have used to store the donation totals for each charity. Explain why you chose your data structure(s). Name of data structure(s)... Description Reason [3] 2210/22/O/N/16 [Turn over

32 4 (b) Write an algorithm to complete Task 2, using either pseudocode, programming statements or a flowchart. You can assume that Task 1 has been completed.... [5] 2210/22/O/N/16

33 5 (c) Explain how you show the totals so far (Task 3). You may include programming statements as part of your explanation.... [6] (d) Explain how you would change your solution for Task 1 to allow the number of charities to be set to two, three or four by the manager.... [3] 2210/22/O/N/16 [Turn over

34 6 Section B 2 Read this section of program code that inputs positive numbers, discards any negative numbers and then outputs the average. An input of zero ends the process. 1 Total = 0 2 Counter = REPEAT 4 REPEAT 5 INPUT Num 6 UNTIL Num < 0 7 Total = Total Counter = Counter + Num 9 UNTIL Num = 0 10 Average = Total / (Counter - 1) 11 Print Average There are four errors in this code. Locate these errors and suggest a correction to remove each error. Error 1... Correction Error 2... Correction Error 3... Correction Error 4... Correction..... [8] 2210/22/O/N/16

35 7 3 The flowchart below inputs an integer. The predefined function DIV gives the value of the division, for example Z 11 DIV 3 gives the value Z = 3. The predefined function MOD gives the value of the remainder, for example Z 11 MOD 3 gives the value Z = 2. Complete a trace table for each of the two input values 33 and 75. Trace table for input value 33 X A B OUTPUT Trace table for input value 75 X A B OUTPUT 2210/22/O/N/16 [4] [Turn over

36 8 4 IF... THEN... ELSE... ENDIF and CASE... OF... OTHERWISE... ENDCASE are two different conditional statements that you can use when writing pseudocode. Explain, using examples, why you would choose to use each conditional statement. Example Reason for choice Example Reason for choice [6] 2210/22/O/N/16

37 9 Question 5 begins on page /22/O/N/16 [Turn over

38 10 5 A database, PLAYPRODUCTION, was set up to show the performance dates, prices and number of seats available at a theatre specialising in Shakespeare productions. Play Performance Date Number Seats Stalls Number Seats Circle Price Stalls Seats $ Price Circle Seats $ As You Like It 01/07/ As You Like It 02/07/ As You Like It 09/07/ Macbeth 14/07/ Macbeth 15/07/ Macbeth 16/07/ Julius Caesar 22/07/ Julius Caesar 23/07/ A Comedy of Errors 30/07/ (a) Give the number of fields that are in each record.... [1] (b) State the data type you would choose for each of the following fields. Play... Number Seats Stalls... Price Stalls Seats $... [3] (c) The query-by-example grid below selects all the productions with more than 100 seats left in either the stalls or the circle. Field: Play Performance Date Number Seats Stalls Number Seats Circle Table: PLAYPRODUCTION PLAYPRODUCTION PLAYPRODUCTION PLAYPRODUCTION Sort: Ascending Show: Criteria: > 100 or: > 100 Show what would be output from the query-by-example.... [3] 2210/22/O/N/16

39 11 (d) Complete the query-by-example grid below to select all the productions with at least six seats left in the circle and show the Play, Performance Date and Price Circle Seats $ in Performance Date order. Field: Table: Sort: Show: Criteria: or: [5] 2210/22/O/N/16

40 12 BLANK PAGE Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge International Examinations Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at after the live examination series. Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge. 2210/22/O/N/16

41 Cambridge International Examinations Cambridge Ordinary Level * * COMPUTER SCIENCE 2210/23 Paper 2 Problem-solving and Programming October/November hour 45 minutes Candidates answer on the Question Paper. No Additional Materials are required. No calculators allowed. READ THESE INSTRUCTIONS FIRST Write your Centre number, candidate number and name in the spaces at the top of this page. Write in dark blue or black pen. You may use an HB pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, glue or correction fluid. DO NOT WRITE IN ANY BARCODES. Answer all questions. DO NOT ATTEMPT TASKS 1, 2 AND 3 in the pre-release material; these are for information only. You are advised to spend no more than 40 minutes on Section A (Question 1). No marks will be awarded for using brand names of software packages or hardware. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. The maximum number of marks is 50. This document consists of 11 printed pages and 1 blank page. DC (LK/SW) /1 [Turn over

42 2 Section A You are advised to spend no longer than 40 minutes answering this section. Here is a copy of the pre-release material. DO NOT attempt Tasks 1, 2 and 3 now. Use the pre-release material and your experience from attempting the tasks before the examination to answer Question 1. Pre-release Material The headteacher of a school needs a program to record and count the votes for a class captain. Each student in the class will be allowed one vote. There can be up to 30 students in a class. Write and test a program for the headteacher. Your program must include appropriate prompts for the entry of data. Error messages and other output need to be set out clearly. All variables, constants and other identifiers must have meaningful names. You will need to complete these three tasks. Each task must be fully tested. TASK 1 Set up the voting Each class can choose from up to four different students as candidates for their class captain. Set up a routine that allows: between two and four different candidate names to be input and stored the candidate names to be displayed with a number (1, 2, 3 or 4) beside each name a choice of 1, 2, 3 or 4 to be entered to record a vote; all other entries are rejected up to four totals set to zero ready to record the votes a maximum of 30 votes to be cast TASK 2 Record and count each vote Input a number 1, 2, 3 or 4; add 1 to the appropriate total. Output the name of the candidate voted for or output invalid vote if a vote is rejected. TASK 3 Show the result When all the votes have been cast, display the candidates names with their totals in descending order of totals. If there is a clear winner, display the candidate s name with the words NEW CLASS CAPTAIN beside it; otherwise display NO OVERALL WINNER. 2210/23/O/N/16

43 1 (a) All variables, constants and other identifiers should have meaningful names. 3 For four of the variables, constants or arrays that you used in Task 1, state the name, data structure, data type and its use. Name 1... Data structure... Data type... Use... Name 2... Data structure... Data type... Use... Name 3... Data structure... Data type... Use... Name 4... Data structure... Data type... Use...[8] 2210/23/O/N/16 [Turn over

44 4 (b) Write an algorithm to complete Task 2, using either pseudocode, programming statements or a flowchart. You can assume that Task 1 has been completed and that there are three candidates for class captain [4] 2210/23/O/N/16

45 5 (c) Explain how you show the result (Task 3). You may include programming statements as part of your explanation....[6] (d) Explain how you could extend your solution to deal with the case of NO OVERALL WINNER....[2] 2210/23/O/N/16 [Turn over

46 6 Section B 2 Read this section of program code that: inputs 10 numbers checks whether each number is within a specified range totals the numbers within the range and outside the range 1 InRange = 0 2 OutRange = FOR Count = 1 TO 10 4 INPUT Num 5 IF Num > 10 AND Num < 20 THEN InRange = InRange ELSE OutRange = OutRange Count = Count NEXT X 9 PRINT InRange, OutRange (a) There are four errors in this code. Locate these errors and suggest a correction to remove each error. Error 1... Correction... Error 2... Correction... Error 3... Correction... Error 4... Correction......[4] 2210/23/O/N/16

47 (b) Decide, with reasons, whether the numbers 10 and 20 are within or outside the range. 7 Number Within range ( ) Outside range ( ) Reason [4] 2210/23/O/N/16 [Turn over

48 8 3 The flowchart below inputs the price of an item under $10. The change from a $10 note is output. Any amount less than 5 cents is rounded up to 5 cents. The predefined function INT rounds a number down to the nearest whole number; for example Z INT(5.7) gives the value Z = 5 START INPUT Price Change 10 Price Is Change >= 1? Yes Dollars INT(Change) No Change Change INT(Change) OUTPUT Dollars, " dollars" Is Change >= 0.5? No Yes Change Change 0.5 OUTPUT "One 50 cent coin" TenCents INT(Change * ) OUTPUT TenCents, " ten cent coins" Is Change*10 TenCents > 0? No Yes OUTPUT "One 5 cent coin" END 2210/23/O/N/16

49 Complete the trace table for the input data: Price Change Dollars TenCents OUTPUT [5] 4 Four validation checks and four descriptions are shown below. Draw a line to link each validation check to the correct description. Validation check Presence check Description Numbers between two given values are accepted Range check Data is of a particular specified type Type check Data contains an exact number of characters Length check Ensures that some data have been entered [3] 2210/23/O/N/16 [Turn over

50 10 5 REPEAT... UNTIL and WHILE... DO... ENDWHILE are two different loop structures you can use when writing pseudocode. Explain, using examples, why you would choose to use each type of loop. Example Reason for choice Example Reason for choice [6] 2210/23/O/N/16

51 11 6 A database, THEATRETOURS, was set up to show the tour dates, towns, number of seats and prices in local currency for a Shakespeare play. Town Tour Date Number of Seats Price Local Currency Wigan 18/08/ Dumfries 20/08/ Turin 25/08/ Macon 27/08/ Bordeaux 29/08/ Algiers 01/09/ Windhoek 05/09/ Windhoek 06/09/ Port Elizabeth 10/09/ (a) Explain why none of the fields in the database can be used as a primary key....[2] (b) State a field that could be added as a primary key. Give a reason for choosing this field....[2] (c) Use the query-by-example grid below to provide a list of tour dates and seat prices in alphabetical order of town. Field: Table: Sort: Show: Criteria: or: [4] 2210/23/O/N/16

52 12 BLANK PAGE Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge International Examinations Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at after the live examination series. Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge. 2210/23/O/N/16