contestada

John can complete a paper route in 20 minutes. Steve can complete the same route in 30 minutes. How long will it take them to complete the route if they work together?

Respuesta :

12 minutes to complete the route together

John can complete a paper route in 20 minutes.

John's 1 minute work = 1/20 , so rate =1/20 job/minute

Steve can complete the same route in 30 minutes

Steve's 1 minute work =1/30, so rate =1/30 job/minute

Together DATA:

Time = y min/job ; Rate = 1/y job/min

rate + rate = together rate

1/20 + 1/30 = 1/y

(30+20)/600 = 1/y

50/600

5/60 = 1/y

y = 60/5 = 12 minutes (time for this to do the job together)