Question 183926

Let x=amount of time needed when both crews are working together
So both crews working together works at the rate of 1/x parking lot per hr
First crew works at the rate of 1/8 parking lot per hr
The other crew works at the rate of 1/10 parking lot per hr

So our equation to solve is:
1/8 + 1/10=1/x  multiply each term by 40x
5x+4x=40
9x=40
x=4.4444444 hrs-------------time needed when both crews are working together

CK
(1/8)*4.444 +(1/10)*4.4444=1 (1 parking lot, that is)
0.555555555 +0.4444444444=1
0.99999999999~~~~~1     close enough


Hope this helps-----ptaylor