Word problem help

Question

Would be thankful if shown how to work properly. 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 four hours. How many hours does it takes the new crew to paint the apartment?

Answer 1

Let x = number of hours for the experienced crew to complete the job

 

Then, 2x = number of hours for the new crew to do the job

 

1/x + 1/(2x) = 1/4

 

4x(1/x + 1/(2x)) = x

 

x = 6 hours