Problema Solution
caroline can paint a fence in 6 hours. her sister lily can paint the same fence in 4 hours. how long will it take them to paint the fence if they work together?
Answer provided by our tutors
Let 'x' be the time they need to paint the whole fence together. Thus we have
Caroline in x hours will paint x/6 parts of the fence
Lily in x hours will paint x/4 parts of the fence
Since they will paint the whole fence in x hours we have
x/6 + x/4 = 1
2x + 3x = 12
5x = 12
x = 2.4 hours
Caroline and Lily will need 2.4 hours to paint the whole fence together.