Question

An experienced computer technician can set up a network in 12 hours. It would take an intern 20 hours to set up the same network. If they work together, how long will it take to set up the network?
I need to know how to find the rate that they work

I need to know how long it will take if they work together

Answer 1

It would be: 1/20+1/12 = 3+5 / 60 = 8/60 = 4/30 = 2/15 = 7.50 hours

so, your answer is 7.50 hours