word problem

Question

Working together, it takes two computers
20
minutes to send out a company's email. If it takes the slower computer
60
minutes to do the job on its own, how long will it take the faster computer to do the job on its own?
Do not do any rounding 

Answer 1

Jordan, we look at how much gets done in one minute.

 

1/60 + 1/x = 1/20

 

Once we have a common denominator (60x),it goes away.

 

x + 60 = 3x

2x = 60

x = 30

 

So, the faster computer can do the job alone in 30 minutes.