SIR MICHELANGELO REFALO

Transcription

1 SIR MICHELANGELO REFALO SIXTH FORM Annual Exam 2014 Subject: Computing ADV 1st Time: 3Hrs Section A Answer all Questions, No Calculators allowed. 1. Write a Boolean expression represented by this Karnaugh Map [3] a. Draw logic gates. [2] Complete the truth table for the circuit below. [2] a. Find the expression of both outputs. [2] b. What is the function of such a circuit? [1] P C Q Page 1 of 6

2 3. Simplify the following Boolean expression using laws. (where A is NOT A) a. X = (A + B ) + (A. B) [2.5] b. X = A. B. C + A. B. C + A. C + A. C [2.5] 4. Convert the following [6] Decimal Unsigned Binary 2 scomplement Sign and Magnitude Using a 16 bit register, 10 for the mantissa and 6 for the exponent (uses 2 s complement) work out the following and normalise letter B and D [4] a b c d Write a short note on the three views of a database (schemas) [5] 7. Prove the 2 De Morgan s laws, [5] 8. Compare and contrast the RAD with the Waterfall model [5] 9. DFDs and USE CASES are 2 methods/tools used during System Analysis, to study how a system works. Write a short not and use examples to explain the 2 tools. [5] Page 2 of 6

3 10. Create a method that generates a random number between two given parameters. The method header is written below. Hint: Use the Math class to generate the random number. [5] public static int numbergenerator(int min, int max) a. Using the previously created method above, write a program that will fill an array of characters with 20 characters (only capital from A to Z). The program should then output the number of times that the letter E occurred in the array. Hint: ASCII codes for letter A is 65 and Z is 90. [5] 11. Using the following tables; Order and Employee to write SQL statements as well as the resultant tables. [5] OrderID CustomerID EmployeeID OrderDate ShipperID EmployeeID LastName FirstName BirthDate Photo 1 Davolio Nancy 12/8/1968 EmpID1.pic 2 Fuller Andrew 2/19/1952 EmpID2.pic 3 Leverling Janet 8/30/1963 EmpID3.pic a. Write an SQL statement to output those Orders (all details) sold by employee name Janet b. Write an SQL statement that will output the name and surname of all employees together with the orders they made. Page 3 of 6

4 Section B Answer any two questions. Each question carries 20 marks. Question 1: Logic A seven-segment display is shown here with the segments labelled a,b,c,d,e,f and g: It is required to display the hexadecimal number from 0 to F, where the hexadecimal numbers A to F should be displayed as shown here: a) Derive the truth tables relating the binary numbers to the displayed hexadecimal numbers. [6] b) Obtain the minimised Boolean expression for the segments a, 2, b,f and g. [10] c) Draw the truth table for the above segments. [4] Page 4 of 6

5 Question 2: Java A real estate agency is looking to computerise its system. The agency carries out two main Operations, which are Selling and Renting. For each operation the details of the operation must be stored in a text file. Details include: Sale ID, Sales person ID, Location, Type of Property, Date and Commission rate. For a Sale of property the Price of sale is stored. While for the Renting, the Start and end date are recorded as well as the price of rent. a. Analyse and model the above system by providing a detailed class diagram. In the diagram include any relevant relations between the classes, Add the Abstract method below (c). [5] b. Using the Class diagram, write the code required to implement the identified classes. Use OOP features including Polymorphism, Encapsulation, Abstraction, and Inheritance. [5] c. Implement an Abstract method that calculates commission. The method should take two parameters; price, commission rate and return the commission in Euro. [5] d. Create a main program that will instantiate the following two Operations below as well as calculating the commission for each operation. [5] Sale: Renting: Sale ID: 87 Sale ID: 123 Sales Person ID: 2100 Sales Person ID: 2471 Location: Gharb Location: Marsalforn Type: Farmhouse Type: Apartment Date: Date: Commission Rate: 5% Commission Rate: 3% Price: 120,000 Euro Start Date: End Date: Price of Rent: 200 Euro Page 5 of 6

6 Question 3: Databases Consider the following database. 1. Normalise the table to third normal form. (Hint: 3 tables should be extracted from the table) [6] 2. Draw an ER diagram of the normalised tables together with an explanation of the tables using standard notation. (Student (id, name ) [5] 3. What is the advantage of Normalising a database over a flat file. [2] 4. Mention and explain 3 functions of a DBMS. [3] 5. Mention 2 things that are to be considered in order to keep the data in a Database safe. 6. Mention and Explain two types of database models [2] [2] Page 6 of 6