Selected MCQ

Current Question
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.
Related Question 1
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 2
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.
Related Question 3
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 4
A can do work 3 times faster than B. If together they finish in 32 hours, how long does A take alone?
  • A. 32 hours
  • B. 48 hours
  • C. 3 days
  • D. 4 days
Correct Answer: A
Explanation:
Work ratio simplifies to A alone time.
Related Question 5
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.