Quick Answer
The answer is tuple, along with str and bytes, as these three are immutable types in Python. Immutability means that once an object is created, its state cannot be changed; any operation that appears to modify it actually creates a new object in memory. For example, concatenating two strings produces a new string rather than altering the original, and the same holds for bytes and tuples. On the Certified Associate Python Programmer PCAP exam, this concept tests your understanding of Python’s core data model, often appearing in multiple-choice questions that ask you to distinguish immutable from mutable types. A common trap is confusing tuple with list or bytearray, both of which are mutable and can be modified in place. To remember, think of the acronym STB: Strings, Tuples, and Bytes are the immutable trio, while lists and bytearrays can change their contents freely.
This PCAP practice question tests your understanding of strings. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. 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 are immutable types in Python?
str
Strings are immutable.
bytes
Bytes objects are immutable.
bytearray
Why wrong: Bytearrays are mutable.
list
Why wrong: Lists are mutable.
tuple
Tuples are immutable.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
str
str, bytes, and tuple are immutable. list and bytearray are mutable.
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.
str
Why this is correct
Strings are immutable.
Related concept
Read the scenario before looking for a memorised answer.
bytes
Why this is correct
Bytes objects are immutable.
Related concept
Read the scenario before looking for a memorised answer.
bytearray
Why it's wrong here
Bytearrays are mutable.
list
Why it's wrong here
Lists are mutable.
tuple
Why this is correct
Tuples are immutable.
Related concept
Read the scenario before looking for a memorised answer.
Common exam traps
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Detailed technical explanation
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
A cloud solutions architect for a retail company is evaluating services for a new workload. The correct answer here reflects best practice for the specific scenario described — not a general cloud recommendation. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Cloud exam questions reward reading the constraint carefully: the same technology can be right or wrong depending on the use case.
What to study next
Identify which PCAP exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
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FAQ
Strings — This question tests Strings — Read the scenario before looking for a memorised answer..
The correct answer is: str — str, bytes, and tuple are immutable. list and bytearray are mutable.
Identify which PCAP exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
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 TWO of the following are immutable in Python?
easyWhy B: Tuple (B) is immutable because once created, its elements cannot be added, removed, or changed. This is enforced by Python's internal structure: tuples are stored as a fixed-length array of PyObject pointers, and any attempt to modify them raises a TypeError.
Last reviewed: Jun 24, 2026
This PCAP 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 PCAP exam.
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