Question

10. Ryan can trim the bushes in the neighbor's yard in 2 hours. Shawn can trim the bushes in 3 hours. If they work together, how long will the job take? a) What is the equation for this calculation? b) How long will the job take? Give the answer in minutes.

Answer 1

1 / (Ryan's rate + Shawn's rate)

72 minutes

Explanation:

Given that :

Ryan's time = 2 hours ; rate = 1 /2

Shawn's time = 3 hours ; rate = 1/3

A.)

Working together :

Take the reciprocal of the sum of Ryan and Shawn's rate

1 / (Ryan's rate + Shawn's rate)

B.) 1/ (1/2 + 1/3)

(1/2 + 1/3) = (3 + 2) / 6 = 5/6

Rate working together = 5/6

Time taken = 1 ÷ (5/6)

= 1 * 6/5

= 6/5 hours = 1.2 hours = (1.2 * 60) = 72 minutes