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Afroditee
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A pump delivered water to fill an empty swimming pool. The pump delive 30 Oct 2022, 13:12
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C
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75% (hard)

Question Stats:

60% (02:55) correct 40% (02:29) wrong based on 238 sessions

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A pump delivered water to fill an empty swimming pool. The pump delivered the water at a constant rate of 450 liters per minute until the pool was 1/2 full. Then the pump became partially clogged and delivered the water at a slower constant rate until the pool was full. For the whole time during which the pump delivered water to fill the empty pool, its average rate was 360 liters per minute. What was the pump`s slower constant rate, in liters per minute?

A. 270
B. 288
C. 300
D. 400
E. 405
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C
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ameya.satyawadi
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A pump delivered water to fill an empty swimming pool. The pump delive 06 Jan 2024, 05:44
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average speed formula when two velocities are given= 2xy/(x+y)

thus 360=2*450*x/(450+x)
360(450+x)=900x
2(450+x)=5x
900=3x
x=300
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martinfzb
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A pump delivered water to fill an empty swimming pool. The pump delive 30 Oct 2022, 16:36
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Let T = total time in minutes to fill the pool, and T1 = time in minutes to fill 1/2 pool
360*T = 450*T1*2
T1/T= 360/900= 2/5
Let x = the constant rate in liters to fill the 2nd half of the pool
then
450*T1+ X*(T-T1)=360*T
450*T1-XT1=360*T-xT,
(450-X)*T1= (360-x)T
T1/T=(360-x)/(450-X)
Since T1/T=2/5
(360-x)/(450-X) =2/5
then X= 300
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A pump delivered water to fill an empty swimming pool. The pump delive 15 Oct 2024, 06:31
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Afroditee
A pump delivered water to fill an empty swimming pool. The pump delivered the water at a constant rate of 450 liters per minute until the pool was 12 full. Then the pump became partially clogged and delivered the water at a slower constant rate until the pool was full. For the whole time during which the pump delivered water to fill the empty pool, its average rate was 360 liters per minute. What was the pump`s slower constant rate, in liters per minute?

A. 270

B. 288

C. 300

D. 400

E. 405
Show more
This seems incorrect. Whats 12 full?
Bunuel - flagging it for review.
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Bunuel
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A pump delivered water to fill an empty swimming pool. The pump delive 15 Oct 2024, 06:47
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glagad
Afroditee
A pump delivered water to fill an empty swimming pool. The pump delivered the water at a constant rate of 450 liters per minute until the pool was 12 full. Then the pump became partially clogged and delivered the water at a slower constant rate until the pool was full. For the whole time during which the pump delivered water to fill the empty pool, its average rate was 360 liters per minute. What was the pump`s slower constant rate, in liters per minute?

A. 270

B. 288

C. 300

D. 400

E. 405
This seems incorrect. Whats 12 full?
Bunuel - flagging it for review.
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That was a typo. Should be 1/2 instead. Fixed. Thank you!
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ZIX
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A pump delivered water to fill an empty swimming pool. The pump delive 18 Oct 2024, 01:38
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It's helpful if you see average rate as: \(\frac{Total Capacity}{Total Time} = \frac{360}{1}\) --- (1). Now add remaining information:

\(\frac{C}{2} = (450)(T1)\)
\(\frac{C}{2} = (R2)(T2)\)

Now simply plug in the values in the eq (1) as:
\(\frac{C}{(C/900)+(C/2R2)} = \frac{360}{1}\)

Solve and you get \(R2 = 300\)
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