document.write( "Question 599515: If a water tank takes 5 minutes to fill and 7 minutes to empty.If the drain is left open when being filled, how long dose it take to fill the tank. \n" ); document.write( "

Algebra.Com's Answer #378990 by w_parminder(53) $\"\"$ $\"About$

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Rate of filling the tank = 1/5
\n" ); document.write( "Rate of emptying the tank = 1/7\r
\n" ); document.write( "\n" ); document.write( "as these two works are exactly opposite in nature, so while filling the tank with its drain open, the combination formula becomes
\n" ); document.write( " $\"1%2FC=1%2F5-1%2F7\"$
\n" ); document.write( " $\"1%2FC=%287-5%29%2F35\"$
\n" ); document.write( " $\"1%2FC=2%2F35\"$ \r
\n" ); document.write( "\n" ); document.write( "C = 35/2 = 17.5\r
\n" ); document.write( "\n" ); document.write( "So the tank would be filled in 17 min & 30 sec \n" ); document.write( "

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