Question

A can complete a job in 10 days and B can complete it in 15 days. How many days will they take together?

Solution

1. A's one-day work = 1/10 and B's one-day work = 1/15.
2. Together, one-day work = 1/10 + 1/15 = 1/6.
3. They complete the job in 6 days.