A can do a work in 10 days, B can do it in 15 days, and C can do it in 20 days. How long will they take to finish the work together?
Q1. A can do a work in 10 days, B can do it in 15 days, and C can do it in 20 days. How long will they take to finish the work together?
Answer: 4.6 days
Explanation: Combined rate = 1 / 10 + 1 / 15 + 1 / 20 = (6 + 4 + 3) / 60 = 13 / 60. Time taken = 1 / (13 / 60) = 60 / 13 = 4.615, approximately 4.6 days.