A and B together can do a job in 12 days. A alone can do it in 20 days. How many days will B alone take?
Q1. A and B together can do a job in 12 days. A alone can do it in 20 days. How many days will B alone take?
Answer: 30 days
Explanation: Together they do 1/12 per day and A does 1/20. B does 1/12 minus 1/20, which is 1/30, so B needs 30 days.