Selected MCQ

Current Question
Three pipes fill a tank in 6 houRs. After 2 hours, one is closed. Remaining time is ____.
  • A. 10
  • B. 12
  • C. 14
  • D. 16
Correct Answer: C
Explanation:
Work-rate adjustment.
Related Question 1
Three pipes of equal capacity fill a tank in 8 houRs. Two pipes will take ____.
  • A. 17 hours
  • B. 12 hours
  • C. 16 hours
  • D. 24 hours
Correct Answer: B
Explanation:
Work is inversely proportional.
Related Question 2
A tap fills a tank in 6 houRs. After half filled, three more taps are opened. Total time is ____.
  • A. 3 hr 15 min
  • B. 3 hr 45 min
  • C. 4 hr
  • D. 4 hr 15 min
Correct Answer: B
Explanation:
Rate increases after half fill.
Related Question 3
A tank is filled in 5 hours by three pipes, A, B, and C. If C is twice as fast as B, find the total time.
  • A. 20 hrs
  • B. 25 hrs
  • C. 35 hrs
  • D. Cannot be determined
Correct Answer: C
Explanation:
Solve rate equations.
Related Question 4
Three pipes fill a tank. The first two together take 15 houRs. Find total time.
  • A. 6 hrs
  • B. 10 hrs
  • C. 15 hrs
  • D. 30 hrs
Correct Answer: C
Explanation:
Combined rate leads to 15 houRs.
Related Question 5
Pipes A, B, C fill tank in 12, 15, 20 houRs. If A alone works, time required is ____.
  • A. 6 hrs
  • B. 6⅔ hrs
  • C. 7 hrs
  • D. 7½ hrs
Correct Answer: C
Explanation:
Based on the given combination.