Question

It takes a groundskeeper 40 minutes to prepare a little League baseball field for a game. It takes his assistant 55 minutes to prepare the same field. How long will it take if they work together to

prepare the field?

Answer 1

23 minutes 9.47 seconds.

Explanation:

The groundskeeper's rate is 1=r*40 so r = 1/40 of the job per minute. The assistant works at a rate of 1/55 of the job per minute (1 = r*55 so r=1/55).

To find the time when they work together, use the equation with their combined rate: 1/40 + 1/55 = 19/440

1 = 19/440 * t so t = 440/19 = 23 and 3/19 minutes or 23 minutes 9.47 seconds.