About this practice. Revision Robin is built and maintained by Bloor Engineering Ltd, a UK-registered company. Our CompTIA Security+ Practice questions are written and reviewed in-house to match the current syllabus, each with a plain-English worked explanation. They are original practice material, not the official exam questions and not affiliated with or endorsed by CompTIA. Always confirm current test rules, fees and content with the official provider at CompTIA. See our Terms and Privacy.
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Q1. Which of the following best describes the security concept of 'non-repudiation'?
A. A user cannot deny having performed an action they took
B. Data is only accessible to authorised parties
C. A system remains available during a failure
D. Data has not been altered in transit
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✓ Answer: A. A user cannot deny having performed an action they took
Non-repudiation ensures a party cannot later deny an action, typically achieved through digital signatures and logging. Confidentiality and availability are separate CIA-triad concepts, and integrity refers to data not being altered.
Q2. An attacker sends a flood of TCP SYN packets with spoofed source addresses to a web server, never completing the handshake, until the server's connection table is exhausted. What is this attack called?
A. SYN flood
B. Smurf attack
C. DNS amplification
D. ARP poisoning
Show answer & explanation
✓ Answer: A. SYN flood
A SYN flood abuses the TCP three-way handshake by sending many SYN packets without completing the ACK, exhausting the server's half-open connection queue. A smurf attack instead abuses ICMP broadcast replies, and DNS amplification abuses open DNS resolvers to magnify traffic toward a victim.
Q3. In a serverless (Function as a Service) architecture, which security concern is most unique compared to traditional server-based deployments?
A. Securing ephemeral, short-lived execution environments and function-level permissions
B. Patching the operating system kernel
C. Configuring RAID for storage redundancy
D. Managing physical rack access
Show answer & explanation
✓ Answer: A. Securing ephemeral, short-lived execution environments and function-level permissions
Serverless functions spin up and tear down quickly, so security focuses on least-privilege execution roles, event source validation, and code-level controls rather than OS patching, which the provider manages. RAID and physical rack access are entirely abstracted away from the customer in serverless models.
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Who has to sit the CompTIA Security+ Practice
Who needs a CompTIA Security+ Practice?
IT professionals seeking entry/advancement in cybersecurity, including junior SOC analysts, security administrators, and government/DoD personnel requiring IAT Level II.
The real CompTIA Security+ Practice: format
How many questions are in the CompTIA Security+ Practice?
The real CompTIA Security+ Practice has 90 questions and lasts 90 minutes. Our mock uses 65 questions in 90 minutes.
What is the CompTIA Security+ Practice pass mark?
Real exam pass mark: 750 (on a scale of 100-900). Our mock marks you at 50 out of 65, the threshold we mark against.
What it costs, and what a resit costs
How much does the CompTIA Security+ Practice cost?
Real exam fee: ~£320 GBP. Resit fee: ~£320 GBP. Rebooking after a fail: No waiting period for the second attempt after the first failure; 14 days between subsequent attempts.
How hard is it
What is the CompTIA Security+ Practice pass rate?
Real exam first-time pass rate: 50-65% (self-study), 70-75% (structured training), 85-93% (bootcamp). Difficulty: Moderately difficult, harder than A+ or Network+, especially for those without prior IT experience.
Why people fail it
Why do people fail the CompTIA Security+ Practice?
Underestimating Performance-Based Questions (PBQs) and lacking hands-on skills.
Memorizing concepts without understanding application in scenario-based questions.
Poor time management, particularly with Performance-Based Questions (PBQs).
Figures for the real exam from vertexaisearch.cloud.google.com, google.com, checked October 2026. Fees and rules change, so confirm with the test provider before you book.
CompTIA Security+ Practice: common questions
Frequently asked
How long do you get?
The test is timed at 90 minutes. Our full mock runs on the same clock so you can practise your pacing.
Are these the real exam questions?
No. Our questions are original and written to match the current syllabus, so they give realistic practice without copying the official paper. Every answer comes with a plain-English explanation. Always confirm current rules and content with CompTIA.