Selected MCQ

Current Question
A and B can do the work in 15 and 10 days. If they start together and A leaves after some days, total time ____.
  • A. 8 days
  • B. 10 days
  • C. 12 days
  • D. 15 days
Correct Answer: C
Explanation:
Solve with work fractions.
Related Question 1
If P finishes work in 18 days and Q in 15 days, and Q leaves after 10 days, remaining work is done in ____.
  • A. 8
  • B. 6
  • C. 4
  • D. 2
Correct Answer: B
Explanation:
Remaining work divided by P’s rate.
Related Question 2
P and Q complete work in 15 and 10 days. Together they complete in ____.
  • A. 6
  • B. 12
  • C. 22
  • D. 20
Correct Answer: A
Explanation:
Combined rate = 1/15 + 1/10 = 1/6 → time = 6 days.
Related Question 3
A can do a piece of work in 15 days while B can do it in 20 days. They work together for 5 days. What fraction of work is left ____.
  • A. 1/4
  • B. 1/3
  • C. 1/2
  • D. 2/3
Correct Answer: A
Explanation:
Work done = 5 × (1/15 + 1/20) = 7/12.
Related Question 4
A can complete the work in 12 days and B in 18 days. In how many days will they complete the work together ____.
  • A. 6 days
  • B. 7.2 days
  • C. 8 days
  • D. 9 days
Correct Answer: B
Explanation:
Combined work = (1/12 + 1/18) = 5/36 → time = 36/5.
Related Question 5
A alone finishes work in 10 days, B in 15 days if they work together, total days ____.
  • A. 35
  • B. 40
  • C. 45
  • D. None
Correct Answer: C
Explanation:
Combined work rate.