PCEP Practice Question: Data Types, Variables, Basic I/O and Operators
A company needs to calculate the average of three test scores entered by a user. The scores are integers. The programmer writes the following code:
s1 = input("Enter score 1: ") s2 = input("Enter score 2: ") s3 = input("Enter score 3: ") avg = (s1 + s2 + s3) / 3
print("Average:", avg)When run, the output is incorrect. What is the most likely cause?
⚠ Common exam trap
Python Institute often tests the misconception that `input()` returns a numeric type, leading candidates to overlook the need for explicit type conversion before arithmetic operations.
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() function returns strings, so concatenation occurs instead of addition.
The `input()` function in Python always returns a string, even when the user types numbers. The `+` operator on strings performs concatenation (e.g., '5' + '3' + '2' becomes '532'), not numeric addition. Dividing the concatenated string by 3 then causes a `TypeError` (or produces an incorrect result if the string is implicitly converted), so the average calculation fails.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The division by 3 will cause a ZeroDivisionError because 3 is not a float.
Why it's wrong here
Division by 3 is valid and does not cause an error.
- ✗
The division operator / always returns an integer, but the sum is not an integer.
Why it's wrong here
In Python, / returns a float, not an integer.
- ✗
The variable names s1, s2, s3 are not allowed because they start with a letter.
Why it's wrong here
Variable names can start with a letter.
- ✓
The input() function returns strings, so concatenation occurs instead of addition.
Why this is correct
input() returns a string, so using + on strings concatenates them.
Quick reference
AWS S3 Storage Class Comparison
| Storage Class | Min Duration | Retrieval | Use Case |
|---|---|---|---|
| S3 Standard | None | Immediate | Frequently accessed data |
| S3 Standard-IA | 30 days | Immediate | Infrequent access, rapid retrieval |
| S3 One Zone-IA | 30 days | Immediate | Non-critical infrequent data |
| S3 Intelligent-Tiering | None | Immediate–hours | Unknown or changing access patterns |
| S3 Glacier Instant | 90 days | Milliseconds | Archive with instant retrieval |
| S3 Glacier Flexible | 90 days | Minutes–hours | Archive, flexible retrieval |
| S3 Glacier Deep Archive | 180 days | Hours | Long-term compliance archive |
Go deeper
Related to this question
About these practice questions
Courseiva writes every PCEP question from scratch — 498 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
Same concept, more angles
1 more way this is tested on PCEP
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A developer writes code to compute the average of two numbers entered by the user: x = input('Enter first number: '); y = input('Enter second number: '); avg = (x + y) / 2. The program produces an error. What is the best practice to fix the code?
easy- A.Convert the result to int after the operation: avg = int((x + y) / 2)
- B.Use int() on the input() values: x = int(input(...)); y = int(input(...))
- C.Use type casting in the division: avg = (float(x) + float(y)) / 2
- ✓ D.Convert x and y to float before the operation: x = float(input(...)); y = float(input(...))
Why D: The `input()` function in Python always returns a string. When you use the `+` operator on two strings, it concatenates them (e.g., '5' + '3' = '53'), not adds them numerically. Dividing a concatenated string by 2 raises a TypeError. The best practice is to convert both inputs to `float` immediately after receiving them, ensuring the subsequent arithmetic works correctly.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.