Sorry not a full solution

Quote:

Originally Posted by **u317dwang**

1. 2 pumps of different sizes, working together, can empty a fuel tank in 5 hours. The larger pump can empty this tank in 4 hours less than the smaller one. If the larger one is out of order, how long will it take the smaller one to do the job alone?

Pump A flowrate = A

Pump B flowrate = B

Volume of fuel tank = T

Number of hours it takes smaller pump(B) to empty tank = x

eq1) 5A + 5B = T

eq2) (x)B =T

eq3) (x-4)A = T

Deleted my bad work:o (thanks rgep and ticbol)