Selected MCQ

Current Question
If X and Y complete a work in 10 days and Y and Z in 16 days, and X and Z in 22 days, how long does each take?
  • A. 120, 40, 60 days
  • B. 120, 60, 80 days
  • C. 40, 30, 120 days
  • D. 30, 40, 60 days
Correct Answer: A
Explanation:
Solving simultaneous equations gives values.
Related Question 1
8 children and 12 men complete work in 9 days if each child takes twice time of a man, time required by men alone ____.
  • A. 6 days
  • B. 8 days
  • C. 10 days
  • D. 12 days
Correct Answer: D
Explanation:
Convert child efficiency to men.
Related Question 2
P completes work in 24 days, Q in 9 days, R in 12 days. Time taken together is ____.
  • A. 10
  • B. 9
  • C. 11
  • D. 12
Correct Answer: A
Explanation:
Sum of rates gives time = 10 days.
Related Question 3
Kamal completes work in 20 days. Suresh is 25% more efficient. Time taken by Suresh is ____.
  • A. 14
  • B. 16
  • C. 15
  • D. 11
Correct Answer: B
Explanation:
Efficiency ↑25% → time = 20/1.25 = 16 days.
Related Question 4
If 9 workers can complete a job in 6 days, how many days will 3 workers take?
  • A. 12
  • B. 15
  • C. 18
  • D. 20
Correct Answer: C
Explanation:
Work = 54 ⇒ 54/3 = 18.
Related Question 5
If 12 men can complete a work in 10 days, how many days will 15 men take?
  • A. 6
  • B. 8
  • C. 10
  • D. 12
Correct Answer: B
Explanation:
Work = constant ⇒ 12×10 = 15×x ⇒ x = 8.