A can do a work in 12 days, B in 15 days, and C in 20 days. How many days will they take to complete the work together?
Q1. A can do a work in 12 days, B in 15 days, and C in 20 days. How many days will they take to complete the work together?
Answer: 5 days
Explanation: The combined rate of work is 1/12 + 1/15 + 1/20 = (5 + 4 + 3)/60 = 12/60 = 1/5. So, they will complete the work in 5 days.