Question

A can do a piece of work in 20 hours, B and C can do it 5 hours whereas A and C can do it in 12 hours. How long will B alone take to do the same work?​

Answer 1

Answer:

So, work per hour done by both A and C = 12/6 = 2 units. So, C alone can complete (2-1) units = 1 unit of work per hour. Given, B and C together can do the work in 3 hours. So, work per hour done by both B and C = 12/3 = 4 units.