Part 1 (80 points) Multiple Choice Questions (20 questions * 4 points per question = 80 points)

Transcription

1 EECS 183 Fall 2013 Exam 1 Part 1 (80 points) Closed Book Closed Notes Closed Electronic Devices Closed Neighbor Turn off Your Cell Phones We will confiscate all electronic devices that we see including cell phones, calculators, etc. Multiple Choice Questions (20 questions * 4 points per question = 80 points) Key 1 Instructions: Read Carefully! 1. This is a closed book exam. You may not refer to any materials during the exam. 2. Some questions are not simple, therefore, read carefully. 3. Assume all code and code fragments are syntactically valid, unless otherwise specified. 4. Assume/use only Python 2 (as taught in class; not Python 3.3+). 5. In all the given code, if any character looks like a space, it is one. 6. On the scantron sheet, bubble in your name and UMID. 7. On the scantron sheet, bubble in Key On the scantron sheet, sign your name to indicate the honor pledge below: I have neither given nor received aid on this examination, nor have I concealed any violations of the Honor Code. Sign your name above Print your uniqname above, LEGIBLY 1

2 1 What does the following expression evaluate to? 13 / % 4 A) 4 A) 3 B) 3.25 D) Which of the following is a keyword in Python? A) int B) void C) float D) return E) All of the above 3 Which of the following is a valid variable name in Python? A) do it B) do+1 C) 1do D) All of the above 4 What does the following print? x = 10 / 4 y = 5 / 2.0 print x + y A) 4 B) 5 C) 4.5 D) 7 2

3 5 Across how many lines will the following program s output appear? print "how\nnow\tbrown/ncow?" A) 2 B) 4 C) 3 D) 1 6 If the user types: 3.5<ENTER> followed by: 2<ENTER>, what is the output? a = raw_input() b = int( raw_input() ) print a * b A) 3.5 B) C) 7 D) 6 7 What does the following code snippet output? x = 'A' print chr( 1 + ord( x ) ) A) A B) x C) B D) y 3

4 8 What does the following code produce as output? i = 1 x = 3 sum = 0 while ( i <= x ): sum += i i += 1 print sum A) 12 B) 6 C) 3 D) 1 9 What does the following line of code print? print "\"Have some cookies!\"\\"# my aunt said" A) "Have some cookies!\" B) "Have some cookies!"# my aunt said C) \ D) "Have some cookies!"\ 10 What does the following Python program display? x = 3 if ( x == 0 ): print "Am I here?", elif ( x == 3 ): print "Or here?", print "Or over here?" A) Am I here? B) Or here? C) Am I here? Or here? D) Or here? Or over here? E) Am I here? Or over here? 4

5 11 Which of the following Boolean expression(s) implement the following statement? x and y are not equal to zero, and they are either both positive or both negative (read carefully) A) ( x < 0 and y < 0 ) or ( x > 0 and y > 0 ) B) ( x * y ) > 0 C) ( x < 0 or x > 0 ) and ( y < 0 or y > 0 ) D) Two of the above are correct E) All of the above are correct 12 If the user inputs: 2<ENTER>, what does the following code snippet print? x = float( raw_input() ) if ( x == 1 ): print "Yes" elif ( x == 2 ): print "Maybe" else: print "No" A) Yes B) No C) Maybe D) Nothing is printed E) This code will not run at all due to an error 13 Given the variables declared below, which expression evaluates to True? a = 3 txt = "fun" limit = 10 words = 5 A) a == limit - words B) not ( words < limit ) C) ( a > limit ) or ( len( txt ) < words ) D) words * a < limit E) ( len( txt ) > 0 ) and ( limit - words < a ) 5

6 14 When the following code runs, how many times is the line x = x * 2 executed? x = 1 while ( x < 20 ): x = x * 2 print x A) 2 B) 5 C) 19 D) 4 E) What is the output when this code executes? x = 1 while ( x <= 5 ): x + 1 print x A) 6 B) 1 C) 4 D) 5 6

7 16 What is the output of this program? def bar( z ): i = 1 while ( i <= z ): i *= 2 return i print i, print bar( 7 ) A) 7 B) 8 C) 7 7 D) What is the output of this Python program, if the user types 3<ENTER> as input? def foo( x ): i = 0 while ( i < x ): print i, i += 1 return i n = int( raw_input() ) foo( n ) A) B) C) 0 1 D) 0 7

8 18 Which input from the user will make this program display 10 as the output? (read carefully) def func( x ): return x + 1 n = int( raw_input() ) print func( n / 2 ) * func( n + 1 ) A) 1 B) 2 C) 3 D) 4 19 What does the following program display? def square( x ): x = x * x print x, return x x = 2 print x, print square( x ), print x A) B) C) D)

9 20 Given the following function description # Returns True if it is possible to add two of the # integers to get the remaining one and False otherwise. # e.g., twoasone(1, 2, 3) returns True # e.g., twoasone(3, 1, 2) returns True # e.g., twoasone(3, 2, 2) returns False # e.g., twoasone(5, 2, 8) returns False Note: Having the return statement at the end of the line is the same as having it on a separate line, indented. For instance, these two are equivalent: if ( a + b == c ): return True if ( a + b == c ): return True Which of the following function definitions produces the desired effect? A) def twoasone( a, b, c ): if ( a + b == c ): return True else: return False if ( a + c == b ): return True else: return False if ( b + c == a ): return True else: return False B) def twoasone( a, b, c ): if ( ( a + b == c ) and ( a + c == b ) and ( b + c == a ) ): return True return False C) def twoasone( a, b, c ): if ( a + b == c ): return True elif ( ( a + c == b ) or ( b + c == a ) ): return True return False D) def twoasone( a, b, c ): if ( a + b!= c ): return False elif ( a + c!= b ): return False elif ( b + c!= a ): return False else: return True 9