Posted by Saige on Thursday, January 19, 2012 at 11:31pm.
Pump A can fill a swimming pool in 6 hours and pump B can fill the same pool in 4 hours. The two pumps began working together to fill an empty pool, but after 40 minutes pump B broke down, and pump A had to complete the job alone. The pool was scheduled to open 4 hours after the pumping started. Was it full by then, or did the opening have to be delayed?

algebra  Steve, Friday, January 20, 2012 at 10:41am
rewording to indicate the rate of completion,
a = 1/6 pool/hr
b = 1/4 pool/hr
they work together for 2/3 hour, so they filled
(1/6 + 1/4)*2/3 = 5/18 pool
So, how long does it take A to fill the other 13/18 pool?
13/18 / 1/6 = 13/3 hour
So, the whole pool took 2/3 + 13/3 = 15/3 = 5 hours to fill, finishing an hour late.
Answer This Question
Related Questions
 Math  The Timuga swimming pool, of Manila City has two pumps it uses to fill ...
 Math  Each of three pumps A, B, C can pump water either into, or out of, a ...
 Algebra I  Pump A, working alone, can fill a tank in 3 hours, and pump B can ...
 math  If pump A and pump B work together, they can fill a pool in 4 hours. Pump...
 college algebra  Pump A alone can empty the city pool in 12 hours. If only pump...
 Algebra  a worker has a new pump and an old pump. the new pump can fill a tank ...
 mathalgebra  one pump can empty a pool in 5 days, wheras a second pump can ...
 math  One pump can empty a pool in 5 days, whereas a second pump can empty the ...
 math  One pump can empty a pool in 5 days, whereas a second pump can empty the ...
 math  One pump can empty a pool in 5 days, whereas a second pump can empty the ...
More Related Questions