P, Q, R can finish a job alone in 6, 8 and 12 days respectively. How long together?
- A2 days 8 hours
- B2 days 16 hours
- C3 days
- D3 days 4 hours
Reveal answer
Correct answer
B.2 days 16 hours
Reveal solution
Combined rate = 1/6 + 1/8 + 1/12 = (4+3+2)/24 = 9/24 = 3/8. Time = 8/3 days = 2 days 16 hours.