Question

P can do a job in 10 days, Q can do the same job in 12 days and R can do the same job in 15 days. In how many days they will finish the work together?

• A. 2
• B. 4
• C. 6
• D. 12

Answer 1

Answer: (B)

4

Amount of work P can do in 1 day = 1/10
Amount of work Q can do in 1 day = 1/12
Amount of work R can do in 1 day = 1/15
Work done by P,Q and R in 1 day = 1/10 + 1/12 + 1/15 =15/60=1/4
Working together, they will complete the work in 4 days.
Answer (B) 4