Problema Solution
if sally can paint a house in 4 hours and john can paint the same house in 6 hours, how long will it take for both of them to paint the house together
Answer provided by our tutors
sally can paint a house in 4 hours, each hour Sally paints 1/4 of the house.
and john can paint the same house in 6 hours, each hour John paints 1/6 of the house.
If they work together, each hour they paint 1/4 + 1/6 of the house.
The time they need to finish the job is 1/(1/4+1/6) = 1/(5/12) = 12/5 = 2 2/5 hours