Discuss Forum
1. A and B together can complete a piece of work in 12 days, B and C can do it in 20 days and C and A can do it in 15days. A, B and C together can complete it in:
- A. 12 days
- B. 12 days
- C. 12 days
- D. 12 days
Answer: Option D
Explanation:
A & B can do in 1 day = 1/12 work
B & C can do in 1 day = 1/20 work
C & A can do in 1 day = 1/15 work
2(A&B&C) can do in 1 day = 1/12 + 1/20 + 1/15 = 12/60 = 1/5 work.
A&B&C can do in 1 day = 1/(5 × 2) = 1/10 work.
Required number of days = 1/(1/10) = 10 days. Ans: D.
B & C can do in 1 day = 1/20 work
C & A can do in 1 day = 1/15 work
2(A&B&C) can do in 1 day = 1/12 + 1/20 + 1/15 = 12/60 = 1/5 work.
A&B&C can do in 1 day = 1/(5 × 2) = 1/10 work.
Required number of days = 1/(1/10) = 10 days. Ans: D.
Post your comments here: