Problema Solution
A roofing contractor estimates that he can shingle a house in 20 h and that his assistant can do it in 30 h. How long will it take them to shingle the home working together?
Answer provided by our tutors
We assume the time working together is t, so the equation is below:
1/t = 1/20 + 1/30
We solve this
t = 12
So it takes 12h if working together