This LFCS practice question tests your understanding of user and group management. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. 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.
A sysadmin set up a shared directory /data/project with group ownership project and permissions 2775 (rwxrwsr-x). Users in the project group can create files, but when they try to edit files created by other group members, they get permission denied. Which is the most likely cause?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The umask of users is set to 027, which prevents group write on new files.
Option A is correct because a umask of 027 would result in new files having permissions 640 (rw-r-----), lacking group write. Option B is wrong because 2775 includes the SGID bit. Option C is wrong because SGID still works with root ownership. Option D is wrong because the sticky bit affects deletion, not editing.
Key principle: Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.
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 directory is owned by root, so files inherit owner root, not the user's primary group.
Why it's wrong here
SGID inherits group ownership regardless of file owner.
✓
The umask of users is set to 027, which prevents group write on new files.
Why this is correct
A umask of 027 results in files with 640 permissions, no group write.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
The SGID bit is not set; the directory must be chmod g+s to enforce group ownership inheritance.
Why it's wrong here
The command already sets 2775, which includes SGID.
Common exam traps
Common exam trap: usable hosts are not the same as total addresses
Subnetting questions often tempt you into counting all addresses. In normal IPv4 subnets, the network and broadcast addresses are not usable host addresses.
Trap categories for this question
Command / output trap
The command already sets 2775, which includes SGID.
Detailed technical explanation
How to think about this question
Subnetting questions test whether you can identify the network, broadcast address, usable range, mask and correct subnet. Slow down enough to calculate the block size correctly.
KKey Concepts to Remember
CIDR notation defines the prefix length.
Block size helps identify subnet boundaries.
Network and broadcast addresses are not usable hosts in normal IPv4 subnets.
The required host count determines the smallest suitable subnet.
TExam Day Tips
→Write the block size before choosing the subnet.
→Check whether the question asks for hosts, subnets or a specific address range.
→Do not confuse /24, /25, /26 and /27 host counts.
Key takeaway
Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.
Real-world example
How this comes up in practice
A network engineer segments a warehouse floor into three subnets: 20 scanners, 5 printers, and 2 management hosts. Picking the wrong mask wastes addresses or leaves too few usable hosts. Exam questions test whether you can apply CIDR notation, calculate block size, and identify the correct usable-host range for a given prefix.
What to study next
Got this wrong? Here's your next step.
Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related LFCS subnetting questions on CIDR, address ranges, and subnet selection.
User and Group Management — This question tests User and Group Management — CIDR notation defines the prefix length..
What is the correct answer to this question?
The correct answer is: The umask of users is set to 027, which prevents group write on new files. — Option A is correct because a umask of 027 would result in new files having permissions 640 (rw-r-----), lacking group write. Option B is wrong because 2775 includes the SGID bit. Option C is wrong because SGID still works with root ownership. Option D is wrong because the sticky bit affects deletion, not editing.
What should I do if I get this LFCS question wrong?
Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related LFCS subnetting questions on CIDR, address ranges, and subnet selection.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
What is the key concept behind this question?
CIDR notation defines the prefix length.
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This LFCS practice question is part of Courseiva's free Linux Foundation 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 LFCS exam.
Question Discussion
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