solving a word problem

Question

A new crew of painters takes two times as long to paint a small apartment as an experienced crew. Together, both crews can paint the apartment in 4 hours. How many hours does it take the new crew to paint the apartment?

It takes _____ hours for the new crew to paint the apartment.

Answer 1

1/x + 1/(2x) = 1/4 <--- they complete the job in 4 hours, so they complete 1/4 of the job per hour

working together

Multiplies both sides by The least common denominator 4x and distributes it

4 + 2 = x

x=6

The new crew has workrate 1/6, so they wil take 6 hours