CSC 141 / QUIZ 3 / UNGRADED PRACTICE

A little practice before Tuesday.

Eleven short questions to help you prepare for Quiz 3. Predict first, choose an answer, then read the explanation.

Quiz: Tuesday, October 27, 2026, 11:00–11:15 AM.
Classes 14–16. Nine multiple-choice questions on loops and strings.

These are different questions from the graded quiz. Practice as often as you like. No name, student ID, or submission is required; this page does not record a grade.

Course home · Quiz 2 practice

What to review

while loops: condition, body, update, and why a missing update never ends.
for + range(start, stop, step): start included, stop excluded, negative steps.
The accumulator and counting patterns, and the reset-inside-the-loop and off-by-one bugs.
Strings: indexing (including negative indexes), slicing, for ch in s, and immutability.

For each snippet, trace the loop one pass at a time with a small table and write the exact output before checking it. The quiz will not ask you to write a complete program.

01 What does this program print?

n = 1
while n < 10:
    print(n)
    n = n * 3

1 3 9 (each on its own line)1 3 9 27 (each on its own line)3 9 (each on its own line)It never stops

02 What values does range(1, 10, 4) produce?1 5 91 51 4 7 104 8

03 What values does range(5, 0, -2) produce?5 3 15 4 3 2 15 3 1 -1nothing

04 What does this program print?

total = 0
for n in range(1, 4):
    total += n
print(total)

6301 2 3

05 What does this program print?

for n in range(1, 4):
    total = 0
    total += n
print(total)

630An error

06 count_evens(6) should return 3. What does this version return?

def count_evens(n):
    count = 0
    for k in range(1, n):
        if k % 2 == 0:
            count += 1
    return count

3240

07 Why does this loop never end?

count = 0
while count < 3:
    print("hi")

count is never changed inside the loop, so count < 3 stays Trueprint() cannot be used inside a while loopThe condition should be count > 3"hi" is a string, not a number

08 What does this program print?

s = "banana"
print(s[0] + s[-1])

babnanIndexError

09 What is the value of "banana"[1:4]?anaananbannan

10 What happens when this program runs?

s = "banana"
s[0] = "B"
print(s)

Prints BananaPrints bananaTypeError: str object does not support item assignmentIndexError

11 What does this program print?

count = 0
for ch in "queue":
    if ch in "aeiou":
        count += 1
print(count)

4250