Problema Solution
scott and rob are going to build birdhouses. rob can build 2 birdhouses in 10 hours longer than it takes Scott to build 1 birdhouse. Together, they can build 4 birdhouses in 7 hours longer than it takes Scott to build 1 birdhouse. How long does it take Scott to build 1 birdhouse?
Answer provided by our tutors
Let 's' and 'r' stand for the rates of scott and rob and let 't' stand for the time it takes Scott to build 1 birdhouse. Using the general equation (number of birdhouses made)=(rate)*(time), we can write:
2=r(t+10)
1=st
4=(r+s)(t+7)
Solving for t, we get:
t=5hrs