Quick Answer
The answer is read only. Bob, as a member of the staff group, is subject to the group permissions on file.txt, which are displayed as r-- in the third through fifth positions of the permission string -rw-r-----. This means the group has read-only access, granting Bob the ability to view the file’s contents but not to modify or delete it, since write permission (w) is absent from the group field. On the CompTIA Linux+ XK0-005 exam, this scenario tests your ability to decode the nine-character permission string and correctly apply the principle that a user’s effective permissions are determined by the most specific matching category—owner, group, or others—with group permissions applying to all members of the assigned group. A common trap is assuming a user inherits the owner’s permissions if they are also the file owner, but here Alice is the owner, not Bob, so only group permissions matter. Remember the mnemonic: “Group gets the middle three—if no w, you can only see.”
This XK0-005 practice question tests your understanding of security. 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.
Refer to the exhibit. $ getfacl file.txt # file: file.txt # owner: alice # group: staff user::rw- user:bob:r-- group::r-- mask::rw- other::---
Refer to the exhibit. Alice is the owner of file.txt. Bob is a member of the staff group. What permissions does Bob have on file.txt?
Refer to the exhibit. $ getfacl file.txt # file: file.txt # owner: alice # group: staff user::rw- user:bob:r-- group::r-- mask::rw- other::---
Read only
The ACL entry 'user:bob:r--' gives read permission.
Read and write
Why wrong: Bob's ACL entry only grants read.
No access
Why wrong: Bob has read access via ACL.
Write only
Why wrong: Bob does not have write permission.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
Read only
Bob is a member of the staff group, and the file.txt permissions are shown as -rw-r-----. The group permissions are r--, meaning members of the staff group (including Bob) have read-only access. The owner (Alice) has read and write, but group permissions do not include write, so Bob cannot modify the file.
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.
Read only
Why this is correct
The ACL entry 'user:bob:r--' gives read permission.
Related concept
Read the scenario before looking for a memorised answer.
Read and write
Why it's wrong here
Bob's ACL entry only grants read.
No access
Why it's wrong here
Bob has read access via ACL.
Write only
Why it's wrong here
Bob does not have write permission.
Common exam traps
CompTIA often tests the misconception that being a member of a group automatically grants the same permissions as the owner, but the trap here is that group permissions are independent and must be examined separately from owner permissions.
Detailed technical explanation
In Linux, file permissions are represented by a 10-character string: the first character indicates file type, followed by three sets of rwx for owner, group, and others. The command 'ls -l' displays these permissions. For file.txt, the group permissions are r-- (read only), meaning any user in the staff group can read the file but cannot write to it. This is enforced by the kernel's permission check during system calls like open() with O_WRONLY or O_RDWR, which would fail with EACCES for write operations.
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 XK0-005 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
Security — This question tests Security — Read the scenario before looking for a memorised answer..
The correct answer is: Read only — Bob is a member of the staff group, and the file.txt permissions are shown as -rw-r-----. The group permissions are r--, meaning members of the staff group (including Bob) have read-only access. The owner (Alice) has read and write, but group permissions do not include write, so Bob cannot modify the file.
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.
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Last reviewed: Jun 30, 2026
This XK0-005 practice question is part of Courseiva's free CompTIA 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 XK0-005 exam.
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