document.write( "Question 960284: a garden hose takes 180 minutes to fill up a hot tub, whereas it takes 300 minutes to drain it, if the drain is accidentally left open how long will it take to fill the hot tub? \n" ); document.write( "
Algebra.Com's Answer #586857 by Theo(13342)![]() ![]() You can put this solution on YOUR website! rate of filling is 1/180 of the tub in one minute. \n" ); document.write( "rate of emptying is 1/300 of the tub in one minute.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "rate * time = quantity. \n" ); document.write( "quantity is 1 full tub. \n" ); document.write( "rate of filling and emptying work against each other, so their rates are subtractive. \n" ); document.write( "time is what you want to find.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "equation becomes:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "(1/180 - 1/300) * T = 1 \n" ); document.write( "multiply both sides of this equation by 180 * 300 and you get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "(300 - 180) * T = 180 * 300\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "simplify to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "120 * T = 180 * 300\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "divide both sides of this equation by 120 to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "T = 180 * 300 / 120\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "simplify to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "T = 450 minutes.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "in 450 minutes, 450/180 = 2.5 times the tub has been filled and 450 / 300 = 1.5 times the tub has been emptied resulting in 1 full tub.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "every minute 1/180 of the tub is being filled and 1/300 of the tub is being empties, result in a net fill of 1/450 of the tub being filled.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "at that rate, the tub will be filled in 450 minutes.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the solution checks out.\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |