A, B, and C can do a job in 10, 15, and 20 days, respectively. How long will they take if they work together?
Q1. A, B, and C can do a job in 10, 15, and 20 days, respectively. How long will they take if they work together?
Answer: 4.7 days
Explanation: Their combined rate = 1/10 + 1/15 + 1/20 = (6 + 4 + 3)/60 = 13/60. So, time taken = 60/13 = 4.615 days.