Question 175 of 498
PCEP Computer Programming and Python Fundamentals Practice Question
A junior developer is writing a script to read a number from input and double it. They write:
num = input("Enter a number: ") result = num * 2
print(result)
When they test with input 5, the output is '55' instead of 10. What is wrong?
⚠ Common exam trap
Candidates often assume `input()` returns a number because the user typed digits, but Python treats all keyboard input as a string, and the `*` operator's string repetition behavior is a classic PCEP trick.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The input is treated as a string; they need to convert it to int.
The `input()` function in Python always returns a string, even if the user types a number. When you use the `*` operator on a string, it repeats the string, so `'5' * 2` yields `'55'`. To perform numeric multiplication, you must convert the input to an integer using `int(input(...))`.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
There is a syntax error in the multiplication line.
Why it's wrong here
The syntax is valid, but produces unexpected results.
- ✗
The print function is incorrectly formatting the output.
Why it's wrong here
print outputs the exact value of result.
- ✗
The variable name 'num' conflicts with a built-in function.
Why it's wrong here
No built-in named 'num' is in scope.
- ✓
The input is treated as a string; they need to convert it to int.
Why this is correct
input() returns a string; string * 2 duplicates the string.
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Last reviewed: Jul 4, 2026
This PCEP practice question is part of Courseiva's free Python Institute certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the PCEP exam.
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