James can paint the office by himself in 7 hours. Manny paints the office in 10 hours. How long will it take them to paint the office working together?

2 answers

1/x = 1/7 + 1/10
Jame's rate = 1office/7 hrs
Manny' rate = 1office/10 hrs
combined rate = 1office/7 + 1office/10
= 17 offices/70 hours

time to do 1 office = 1office/(17offices/70 hours) = 70/17 hours
= appr 4 hours and 7 minutes