document.write( "Question 585491: when the tub is on full, it can fill the tub to overflowing in 20 minutes (ignore overflow drain). the tub's drain can empty the tub in 15 minutes. My four-year-old has turned the faucet on full and the drain is closed. just as the tub starts to overflow, I run in to turn it off, but the handle breaks off, leaving the water running at full power. I yank the drain open.How long will it take the tube to empty, with the faucet still on, but the drain is now open? \n" ); document.write( "

Algebra.Com's Answer #373392 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

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when the tub is on full, it can fill the tub to overflowing in 20 minutes (ignore overflow drain).
\n" ); document.write( "the tub's drain can empty the tub in 15 minutes.
\n" ); document.write( "My four-year-old has turned the faucet on full and the drain is closed.
\n" ); document.write( " just as the tub starts to overflow, I run in to turn it off, but the handle breaks off, leaving the water running at full power.
\n" ); document.write( " I yank the drain open.
\n" ); document.write( "How long will it take the tube to empty, with the faucet still on, but the drain is now open?
\n" ); document.write( ":
\n" ); document.write( "Let t = time required to empty the tub with both faucet and drain open
\n" ); document.write( "Let the completed job = 1 (An empty tub)
\n" ); document.write( ":
\n" ); document.write( " $\"t%2F15\"$ - $\"t%2F20\"$ = 1
\n" ); document.write( "multiply by 60 to clear the denominators
\n" ); document.write( "60* $\"t%2F15\"$ - 60* $\"t%2F20\"$ = 60
\n" ); document.write( "cancel the denominators
\n" ); document.write( "4t - 3t = 60
\n" ); document.write( "t = 60 minutes to empty the tub
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "Check this
\n" ); document.write( " $\"60%2F15\"$ - $\"60%2F20\"$ = 1 \n" ); document.write( "

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