Pipe A can fill a pool in 12 hours. After it has been used for 4.5 hours, Pipe B is also used and the pool is filled in 4.5 hours also. How long would it take Pipe B to fill the pool himself?

see below how I did it. please write the steps thanks :D

http://www.slimber.com/index.php?image=math-problem-3.g150049

Question

Pipe A can fill a pool in 12 hours. After it has been used for 4.5 hours, Pipe B is also used and the pool is filled in 4.5 hours also. How long would it take Pipe B to fill the pool himself?

see below how I did it. please write the steps  thanks :D

http://www.slimber.com/index.php?image=math-problem-3.g150049

anonymous · Answer

sry ! i got the answer. but I can still see if i got the right answer. so go ahead!

anonymous · Answer

Common denominator 12x:
4.5 x + 4.5 *12 = 12x
->            7.5x = 54
=>                x = 54/ 7/5 = 7.2 hr = 7hrs 12min

anonymous · Answer

ahah yay! i got the right answer, but I solved it a different way. but that confirmes it even more! yay! thankss! :D

anonymous · Answer

:)