document.write( "Question 509222: Officials begin to release water from a full man-made lake at a rate that would empty the lake in 18 weeks,but a river that can fill the lake in 25 weeks is replenishing the lake at the same time. How long does it take to empty the lake? \n" ); document.write( "
Algebra.Com's Answer #341336 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
Officials begin to release water from a full man-made lake at a rate that would empty the lake in 18 weeks,but a river that can fill the lake in 25 weeks is replenishing the lake at the same time. How long does it take to empty the lake?
\n" ); document.write( "------------------
\n" ); document.write( "Empty rate = 1/18 job/week
\n" ); document.write( "---
\n" ); document.write( "Fill rate = 1/25 job/week
\n" ); document.write( "---
\n" ); document.write( "Together rate: 1/x
\n" ); document.write( "---
\n" ); document.write( "Equation:
\n" ); document.write( "rate - rate = together rate
\n" ); document.write( "1/18 - 1/25 = 1/x
\n" ); document.write( "----
\n" ); document.write( "Multiply thru by 18*25x
\n" ); document.write( "---
\n" ); document.write( "25x - 18x = 18*25
\n" ); document.write( "7x = 18*25
\n" ); document.write( "x = 64.29 weeks (time required to empty)
\n" ); document.write( "===================
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
\n" ); document.write( " \n" ); document.write( "
\n" );