5.34. Functions with Loops Multiple Choice Questions

Q-1: Given the code below, what would the function print?

def countodd(lst):
   num_of_odd = 0
      for item in lst:
         if item % 2 == 1:
            num_of_odd += 1

   return num_of_odd

print(countodd([1,2,3,4,5]))

• 1
• Try again! This function uses modulus to find the amount of odd numbers in the list that is passed in.
• 2
• Try again! This function uses modulus to find the amount of odd numbers in the list that is passed in.
• 3
• Correct!
• 4
• Try again! This function uses modulus to find the amount of odd numbers in the list that is passed in.
• 5
• Try again! This function uses modulus to find the amount of odd numbers in the list that is passed in.

Q-2: After how many iterations will this code execute the break?

def divide_by_two_until_one(num):
   count = 0
   while (True):
      num = num/2
      count = count + 1
      if (num <= 1):
         break
   return count

print(divide_by_two_until_one(50))

• 50
• Try again! This function will divide the number that is passed in by two until it reaches one.
• 25
• Try again! This function will divide the number that is passed in by two until it reaches one.
• 5
• Try again! This function will divide the number that is passed in by two until it reaches one.
• 6
• Correct!
• 2
• Try again! This function will divide the number that is passed in by two until it reaches one.

Q-3: Which of the following values for x, y, and z would result in the function returning “True”?

def addition(x,y,z):
   if (x + y) == z:
      return "True"
   else:
      return "False"

• x = 5, y = 6, z = 11
• Correct!
• x = 1, y = 5, z = 6
• Correct!
• x = 1, y = 3, z = 10
• Try again! The value of z should be 4 in order to return "True".
• x = -2, y = 1, z = -1
• Correct!
• x = 50, y = 41, z = 94
• Try again! The value of z should be 91 in order to return "True".

Q-4: How many times would "Hello world!" print?

for i in range(4):
   print("Hello world!")

• 3
• Try again! The in range function has an inclusive end value.
• 4
• Correct!
• 0
• Try again! The in range function has an inclusive end value.
• 5
• Try again! The in range function has an inclusive end value.

Q-5: How many times does the following code print and in what pattern?

lst1 = [1, 3, 5, 7]
lst2 = [2, 4, 6, 8, 10]

for x in lst1:
   for y in lst2:
      print(x * y)

• It prints 19 times and it skip counts by the current value in lst2.
• Try again! For loops include the last element.
• It prints 20 times and it skip counts by the current value in lst1.
• Try again! This code counts by the second list.
• It prints 19 times and it skip counts by the current value in lst1.
• Try again! For loops include the last element and count by the second list.
• It prints 20 times and it skip counts by the current value in lst2.
• Correct!

Q-6: What does the following code print?

out = ""
for i in range(2):
    for j in range(2):
        out += "i: " + str(i) + " j:" + str(j) + ", "
print(out)

• i: 0 j: 0, i: 1 j: 1,
• The inner loop will loop twice for each value of i.
• i: 0 j: 0, i: 1 j: 1, i: 2 j: 2,
• The values of i and j will range from 0 to 1.
• i: 1 j: 1, i: 1 j: 2, i: 2: j: 1, i:2: j:2,
• The values of i and j will range from 0 to 1.
• i: 0 j: 0, i: 0 j: 1, i: 1: j: 0, i:1: j:1,
• Correct! The values of i and j range from 0 to 1 and the inner loop executes twice each time i changes.

Q-7: What does the following code print?

l1 = [1, 2]
l2 = [3, 4]
out = []
for val1 in l1:
    for val2 in l2:
        out.append(val1 + val2)
print(out)

• [4, 6]
• This would be true if there was a single loop using an index to loop though both lists
• [4, 5, 5, 6]
• It adds l1[0] and l2[0], then l1[0] and l2[1], then l1[1] and l2[0], then l1[1] and l2[1].
• [1, 2, 3, 4]
• This would be true if the two loops were one after the other instead of nested and it just added the value in each list
• [13, 14, 23, 24]
• The + adds the numbers together, it does not concatenate them.

Q-8: What does the following code print?

l1 = [1, 2, 3]
l2 = [4, 5]
out = []
for val1 in l1:
    for val2 in l2:
        out.append(val1 + val2)
print(out)

• [5, 7]
• This would be true if there was a single loop using an index to loop though both lists but only to the length of the smallest.
• [5, 6, 7, 6, 7, 8]
• This would be true if it looped through l2 and then l1 in the inner loop.
• [5, 6, 6, 7, 7, 8]
• For every value in l1 it loops through all the values in l2.
• [14, 15, 24, 25, 34, 35]
• The + adds the numbers together, it does not concatenate them.

Q-9: What does the following code print?

l1 = [1, 2, 3]
l2 = [4, 5]
out = []
for val1 in l2:
    for val2 in l1:
        out.append(val1 + val2)
print(out)

• [5, 7]
• This would be true if there was a single loop using an index to loop though both lists but only to the length of the smallest.
• [5, 6, 7, 6, 7, 8]
• For every value in l2 it loops through all the values in l1.
• [5, 6, 6, 7, 7, 8]
• This would be true if looped through l1 and then l2 in the inner loop.
• [41, 42, 43, 51, 52, 53]
• The + adds the numbers together, it does not concatenate them.

Q-10: What does the following code print?

l1 = ['1', '2', '3']
l2 = ['4', '5']
out = []
for val1 in l1:
    for val2 in l2:
        out.append(val1 + val2)
print(out)

• [5, 7]
• This would be true if there was a single loop using an index to loop though both lists but only to the length of the smallest and the items were numbers.
• [5, 6, 7, 6, 7, 8]
• This would be true if it looped through l2 and then l1 in the inner loop and the list items were numbers.
• [5, 6, 6, 7, 7, 8]
• This would be true if it looped through l1 and then l2 in the inner loop and the list items were numbers.
• ['14', '15', '24', '25', '34', 35']
• Since the list items are strings the + will concatenate the values.

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