City Guilds Model Questions Vol1 2025 Engineering Question 28

Practice objective / multiple choice question 28 from the 2025 City Guilds Model Questions Vol1 Engineering examination.

City Guilds Model Questions Vol1 2025 Engineering Objective / Multiple Choice Hard Difficulty
Question 28 CITY_GUILDS_MODEL_QUESTIONS_VOL1 • 2025 • ENGINEERING • objective

Three components of a machine have independent exponential lifetimes with mean times to failure of \(2000\) h, \(2500\) h and \(3000\) h respectively. The components are arranged in series, so the machine fails when any component fails. When a component fails it is immediately replaced, incurring no downtime.\n\n(a) Determine the mean time between machine failures (MTBF) in hours.\n(b) Estimate the expected number of component replacements that will occur during \(10\,000\) operating hours of the machine.

Answer Options

A. MTBF = 860 h; expected replacements ≈ 12.00
B. MTBF = 825 h; expected replacements ≈ 11.80
Correct Answer C. MTBF = 810 h; expected replacements ≈ 12.35
D. MTBF = 795 h; expected replacements ≈ 13.20
Correct Answer
C
Correct Option:
MTBF = 810 h; expected replacements ≈ 12.35

About This Question

This is City Guilds Model Questions Vol1 2025 Engineering Question 28. It is one of the objective questions from the 2025 City Guilds Model Questions Vol1 Engineering examination.

Difficulty level: Hard .

View More City Guilds Model Questions Vol1 2025 Engineering Questions More City Guilds Model Questions Vol1 Practice Questions Back to Questions

Master the Exam!

You've seen a preview, but there are thousands more questions plus AI tutor to break down complex solutions.

Unlock Full Access Available for Android & Windows
Chat with Support