Selected MCQ

Current Question
A and B can do the work in 10 days. B alone can do it in 15 days. A alone will take ____.
  • A. 20 days
  • B. 25 days
  • C. 30 days
  • D. 35 days
Correct Answer: C
Explanation:
A’s rate = 1/10 − 1/15 = 1/30.
Related Question 1
A, B, and C can complete work in 8, 14, and 16 days. How many days will A alone take?
  • A. 13
  • B. 11
  • C. 12
  • D. 15
Correct Answer: A
Explanation:
Derived from partial work relation.
Related Question 2
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 3
Four men and two women can complete the work in 2 days. If two men alone take 5 days, how many days will four women take to complete the work ____.
  • A. 15 days
  • B. 10 days
  • C. 8 days
  • D. 20 days
Correct Answer: B
Explanation:
Use work equations: 4M+2W = work/2 and 2M = work/5 → solve for W.
Related Question 4
12 children take 16 days to finish work. Time for the same work with a different number is ____.
  • A. 3 days
  • B. 4 days
  • C. 6 days
  • D. 8 days
Correct Answer: C
Explanation:
Work is inversely proportional.
Related Question 5
If Q alone does work in 12 days and P is twice as fast, time together is ____.
  • A. 1
  • B. 2
  • C. 3
  • D. 4
Correct Answer: D
Explanation:
The combined rate gives 4 days.