document.write( "Question 757513: a swimming pool consists of 4 taps,for first tap it takes 1 hour,for second tap it takes 2 hours,for third tap it takes 3 hours and for fourth tap it takes 4 hours.how much time the swimming pool will take to fill up if all taps are opened? \n" ); document.write( "
Algebra.Com's Answer #460849 by fcabanski(1391)\"\" \"About 
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The first tap fills 1/60 of the pool per minute (1/(60*1)).


\n" ); document.write( "The second tap fills 1/120 of the pool per minute (1/(60*2))


\n" ); document.write( "The third tap fills 1/180 of the pool per minute.


\n" ); document.write( "The fourth tap fills 1/240 of the pool per minute.


\n" ); document.write( "The formula for a job is Job (usually 1) = rate times time.


\n" ); document.write( "The rate is 1/60 + 1/120 + 1/180 + 1/240 = 12/720 + 6/720 + 4/720 + 3/720 = 25/720 = 5/144 of the pool per minute.


\n" ); document.write( "1 = 5/144 * t


\n" ); document.write( "1 * 144/5 = t = approximately 28.8 minutes, or 28 minutes, 48 seconds.


\n" ); document.write( "You can also express the rates as hourly. The first tap fills 1 pool per hour. The second fills 1/2 pool per hour. The third fills 1/3 pool per hour. The fourth fills 1/4 pool per hour. The combined rate is 1 + 1/2 + 1/3 + 1/4 = 12/12 + 6/12 + 4/12 + 3/12 = 25/12 of the pool per hour.


\n" ); document.write( "1 = 25/12 * t


\n" ); document.write( "12/25 = 5 = .48 hours = 28.8 minutes = 28 minutes, 48 seconds.\r
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