EX200 Essential Tools Practice Question
A system administrator runs the command 'ls -l' and sees that a file has permissions '-rwxr-xr-x'. The administrator wants to remove execute permission for the group and others while keeping it for the owner. Which chmod command should be used?
⚠ Common exam trap
It's easy for candidates to confuse the symbolic notation (u, g, o, a) and may incorrectly choose 'chmod u-x' thinking it affects group/others, or they misapply numeric modes like 755 which set permissions absolutely rather than modifying them incrementally.
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
✓
chmod go-x file
The command 'chmod go-x file' removes execute permission for group (g) and others (o) while leaving the owner's permissions unchanged. The current permissions '-rwxr-xr-x' indicate owner has rwx, group has r-x, and others have r-x, so removing execute from group and others yields '-rwxr--r--'.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
chmod u-x file
Why it's wrong here
chmod u-x file removes execute permission only from the file owner (the user class), leaving group and other classes' execute bits exactly as they were. If the intended goal is to strip execute access from group and others, this command does nothing for those classes and actually may leave them with execute permission intact, so it does not achieve the required result.
- ✗
chmod 755 file
Why it's wrong here
chmod 755 file sets the permission bits to rwxr-xr-x, meaning the owner has read/write/execute while group and others receive only read and execute. This symbolic/numeric mode explicitly grants execute permission to the group and other classes rather than removing it, so it is the opposite of the desired action and leaves group and other users still able to execute the file.
- ✓
chmod go-x file
Why this is correct
chmod go-x file is correct because the symbolic mode 'go-x' targets the group (g) and other (o) permission classes with a minus operation, stripping only their execute bits. The owner's existing execute permission is unaffected, which precisely matches the requirement to remove execute access from group and others while preserving the owner's access.
- ✗
chmod a+x file
Why it's wrong here
chmod a+x file adds the execute bit to all three permission classes: user, group, and other. Rather than removing execute from group and others, this command ensures that everyone, including those two classes, has execute permission, so it directly contradicts the stated goal and would increase access instead of restricting it.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This EX200 practice question is part of Courseiva's free Red Hat 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 EX200 exam.