document.write( "Question 575067: An inverted square pyramid has a height equal to 8 meters and a top edge to 3 meters. Initially, it contains water to the depth of 5 meters.
\n" ); document.write( " a. What is the initial volume of the water in the tank?
\n" ); document.write( " b. If the additional water is to be pumped into the tank at the rate of 20 gallons per minute, how many hours will it take to fill the tank?
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Algebra.Com's Answer #369455 by KMST(5328)\"\" \"About 
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For a square base pyramid
\n" ); document.write( "s=length of base side (in meters)
\n" ); document.write( "h=height (in meters
\n" ); document.write( "V=volume (in cubic meters
\n" ); document.write( "\"V=%281%2F3%29s%5E2%2Ah\"
\n" ); document.write( "The inverted pyramid tank has A volume of
\n" ); document.write( "\"V=%281%2F3%293%5E2%2A8=%281%2F3%29%2A9%2A8=24\" cubic meters
\n" ); document.write( "a. The initial volume of water in the tank is the volume of a similar pyramid with
\n" ); document.write( "a height of 5 meters. Since the this pyramid and the 8 meter high pyramid are similar, with a height ratio of
\n" ); document.write( "\"5%2F8\", the ratio of their volumes is \"%285%2F8%29%5E3\"
\n" ); document.write( "So the initial volume of water in the tank is
\n" ); document.write( "\"%285%2F8%29%5E3%2A24=75%2F64=5.859375\" cubic meters
\n" ); document.write( "b.Since the tank's volume was 24 cubic meters, the amount of water that must be added to fill the tank (in cubic meters) is
\n" ); document.write( "\"24-75%2F64=24-5.859375=18.140625\"
\n" ); document.write( "One cubic meter is 1000 liters and one US gallon is approximately 3.79L, so we approximate and convert
\n" ); document.write( "\"%2818.14m%5E3%29%281000L%2Fm%5E3%29%281gallon%2F3.79L%29\"=approximately 4786 gallons
\n" ); document.write( "At 20 gallons per minute, with 60 minutes per hour, the hours needed to fill the tank are
\n" ); document.write( "\"%284786gallons%29%281minute%2F20gallons%29%281hour%2F60minutes%29\"= approximately 3.99hours, so we'll say that thew answer is 4 hours.
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