An empty swimming pool

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An empty swimming pool

by gmatnmein2010 » Fri Feb 19, 2010 7:51 pm
An empty swimming pool with a capacity of 100,000 liters is to be filled by hoses A and B simultaneously, with both hoses starting at the same time and flowing constantly until the pool is full. If the amount of water flowing from each hose is independent from the amount flowing from the other hose, how long will it take to fill the pool?

1) If hose A stopped filling the pool after hoses A and B had filled 1/3 of the pool, it would take 22 hours for hose B to finish filling the pool.
2) If hose B stopped filling the pool after hoses A and B had filled ½ of the pool, it would take 17 hours for hose A to finish filling the pool
Source: — Data Sufficiency |

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by thephoenix » Fri Feb 19, 2010 8:10 pm
gmatnmein2010 wrote:An empty swimming pool with a capacity of 100,000 liters is to be filled by hoses A and B simultaneously, with both hoses starting at the same time and flowing constantly until the pool is full. If the amount of water flowing from each hose is independent from the amount flowing from the other hose, how long will it take to fill the pool?

1) If hose A stopped filling the pool after hoses A and B had filled 1/3 of the pool, it would take 22 hours for hose B to finish filling the pool.
2) If hose B stopped filling the pool after hoses A and B had filled ½ of the pool, it would take 17 hours for hose A to finish filling the pool
IMO C

We need to know rate for each hoses. First statement gives us rate for B, second statement gives us rate for A. So, C.

1) 22 hours * 3/2 = 33 hours (it would take for hose B to fill the empty pool)
insuff
2) 17 hours * 2/1 = 34 hours (it would take for hose A to fill the empty pool)
insuff

if both hoses work together:
t*1/33 + t*1/34 = 1 ---> t = 33*34/(33+34) ~ 33.5 hours

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by shashank.ism » Sun Feb 21, 2010 4:33 am
gmatnmein2010 wrote:An empty swimming pool with a capacity of 100,000 liters is to be filled by hoses A and B simultaneously, with both hoses starting at the same time and flowing constantly until the pool is full. If the amount of water flowing from each hose is independent from the amount flowing from the other hose, how long will it take to fill the pool?

1) If hose A stopped filling the pool after hoses A and B had filled 1/3 of the pool, it would take 22 hours for hose B to finish filling the pool.
2) If hose B stopped filling the pool after hoses A and B had filled ½ of the pool, it would take 17 hours for hose A to finish filling the pool
cap. = 100,000 lit.
St.1) time taken by B to full empty pool = 3/2 x 22 = 33 hrs.we don't know abt A
insufficient
St.2) time taken by A to full empty pool = 2 x 17 = 34 hrs.we don't know abt B
insufficient

combined : time = 1/(1/33 +1/34) suff..Ans C
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