A is 50% more efficient than B. C does half of the work done by A and B together in the same time. If C alone can do the work in 30 days, then A, B and C together can do the work in: MCQ with Answer and Explanation

A is 50% more efficient than B. C does half of the work done by A and B together in the same time. If C alone can do the work in 30 days, then A, B and C together can do the work in:
A. 12 days
B. 10 days
C. 20 days
D. 15 days
Answer: Option B
Solution (By JKSSB Mock Tests)
Let efficiency of B = 2, then efficiency of A = 3. Combined efficiency of A and B = 5. Efficiency of C = 5 / 2 = 2.5. Total work = Efficiency of C * Time of C = 2.5 * 30 = 75 units. Combined efficiency of A, B and C = 3 + 2 + 2.5 = 7.5 units/day. Time taken together = 75 / 7.5 = 10 days.

Discuss this Question (0)

No comments yet. Be the first to start the discussion!

Practice More Time and Work Questions

Question #1
A can complete a work in 19 days and B in 41 days. If both work together, in how many days will the work be completed?
A. 12.98
B. 15.48
C. 20.48
D. 17.98

Correct Answer: Option A


Explanation:
Combined rate = 1/19 + 1/41. Time = 12.98 days.

This question belongs to: Maths Time and Work
Question #2
A can complete a work in 16 days and B in 29 days. If they work together, the work will be completed in:
A. 15.31
B. 20.31
C. 10.31
D. 25.31

Correct Answer: Option C


Explanation:
Combined rate = 1/16 + 1/29. Required time = 10.31 days.

This question belongs to: Maths Time and Work
Question #3
If 8 men and 12 boys can finish a piece of work in 10 days, while 6 men and 8 boys can finish it in 14 days, find the time taken by 1 man alone to complete the work.
A. 120 days
B. 160 days
C. 140 days
D. 100 days

Correct Answer: Option C


Explanation:
Total work = 10 * (8M + 12B) = 14 * (6M + 8B) => 80M + 120B = 84M + 112B => 4M = 8B => 1M = 2B. Total work = 10 * (8M + 6M) = 140M. Thus, 1 man alone will take 140 days.

This question belongs to: Maths Time and Work