A, B, and C can complete a work in 10, 15, and 20 days, respectively. How many days will they take to complete the work together?
Q1. A, B, and C can complete a work in 10, 15, and 20 days, respectively. How many days will they take to complete the work together?
Answer: 4.7 days
Explanation: The combined rate of work is 1/10 + 1/15 + 1/20 = (6 + 4 + 3)/60 = 13/60. So, the time taken is 60/13 = 4.615 days.