Quick Answer
The answer is that dictionaries are mutable, while tuples are immutable. This distinction is fundamental to understanding Python data types because mutability determines whether an object’s state can be changed after creation. Dictionaries allow you to add, remove, or modify key-value pairs, making them mutable, whereas tuples, once defined, cannot have their elements altered, added, or removed—this immutability is what makes tuples hashable and usable as dictionary keys, unlike lists. On the Certified Entry-Level Python Programmer PCEP exam, this concept tests your grasp of core data type behavior, often appearing in multiple-select questions that ask you to identify which statements about mutability are correct. A common trap is confusing tuples with lists, since both store ordered sequences, but remember: lists are mutable and tuples are not. For a quick memory tip, think of a tuple as a “locked list”—once you pack it, you cannot change its contents.
This PCEP practice question tests your understanding of computer programming and python fundamentals. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
Which THREE of the following statements about Python data types are correct? (Choose three.)
Strings are mutable.
Why wrong: Strings are immutable.
Sets are immutable.
Why wrong: Sets are mutable (though elements must be immutable).
Tuples are immutable.
Tuples cannot be changed after creation.
Lists are mutable.
Lists can be changed after creation.
Dictionaries are mutable.
Dictionaries can be modified.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
Tuples are immutable.
Option C is correct because tuples in Python are immutable, meaning once created, their elements cannot be changed, added, or removed. This immutability makes tuples hashable and usable as dictionary keys, unlike lists.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
Strings are mutable.
Why it's wrong here
Strings are immutable.
Sets are immutable.
Why it's wrong here
Sets are mutable (though elements must be immutable).
Tuples are immutable.
Why this is correct
Tuples cannot be changed after creation.
Related concept
Read the scenario before looking for a memorised answer.
Lists are mutable.
Why this is correct
Lists can be changed after creation.
Related concept
Read the scenario before looking for a memorised answer.
Dictionaries are mutable.
Why this is correct
Dictionaries can be modified.
Related concept
Read the scenario before looking for a memorised answer.
Common exam traps
The trap here is that candidates often confuse the immutability of strings and tuples with the mutability of lists and dictionaries, or incorrectly assume sets are immutable because their elements must be immutable.
Detailed technical explanation
Immutability in Python is enforced at the object level: for tuples, the internal C structure (PyTupleObject) does not support item assignment, and any attempt raises a TypeError. This design allows tuples to be used as dictionary keys and to be placed in sets, while lists and dictionaries, which are mutable, cannot. In real-world scenarios, using a tuple for fixed data like coordinates or RGB values ensures accidental modification is prevented.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
A practitioner preparing for the PCEP exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
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FAQ
Computer Programming and Python Fundamentals — This question tests Computer Programming and Python Fundamentals — Read the scenario before looking for a memorised answer..
The correct answer is: Tuples are immutable. — Option C is correct because tuples in Python are immutable, meaning once created, their elements cannot be changed, added, or removed. This immutability makes tuples hashable and usable as dictionary keys, unlike lists.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Same concept, more angles
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. Which THREE of the following are Python data types? (Choose three.)
mediumWhy A: A is correct because `float` is a built-in Python numeric data type used to represent floating-point numbers (e.g., 3.14, -0.001). It is one of the core immutable types in Python, distinct from integers and complex numbers.
Last reviewed: Jun 11, 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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