document.write( "Question 394161: A swimming pool is 15 ft by 30 ft by 5 ft. It takes 25 minutes longer to fill than to drain the pool. It can be drained at a rate of 15ft cubed per minute faster than it can be filled, what is the drainage rate? \n" ); document.write( "

Algebra.Com's Answer #279655 by ewatrrr(24785) $\"\"$ $\"About$

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document.write( "Hi, Note**
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document.write( "V(pool) = 15*30*5 ft^3 = 2250 ft^3
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document.write( "**drained at a rate of 15ft cubed per minute faster than it can be filled
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document.write( "Let x and (x+15)represent the fill and drainage rates respectively 
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document.write( "Question States:  t(drain) = 2250 ft^3/(x+15) 
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document.write( " t(fill) = 2250 ft^3/(x+15) + 25 = 2250/x     |takes 25 minutes longer to fill
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document.write( " 2250 ft^3/(x+15) + 25 = 2250/x 
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document.write( " 2250x + 25x(x+15) = 2250(x+15)  
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document.write( " 25x^2 + 375x - 33750 = 0 
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document.write( "   x^2 +15 - 1350 =0
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document.write( "factoring 
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document.write( " (x +45)(x-30)=0
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document.write( " (x +45)= 0 tossing out negative solution
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document.write( " (x-30)=0  x = 30 ft^3/min, fill rate.  Drainage rate is 45 ft^2/min  (30+15)\r
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document.write( "CHECKING our Answer
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document.write( "t(drain)=2250/45 = 50min  t(fill)= 2250/30 = 75min   (25min longer)\r
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