document.write( "Question 1053962: My word Problem is this: A tank can be filled by one pump in 50 minutes and by another pump in 60 minutes. A third pump can drain the tank in 75 minutes. If all 3 pumps go into operation, how long will it take to fill the tank?\r
\n" ); document.write( "\n" ); document.write( "I have made a table like this:\r
\n" ); document.write( "\n" ); document.write( "Pump | Minutes | In One Minute | In x minutes\r
\n" ); document.write( "\n" ); document.write( "P1 | 50 | 1/50 | 1/50x\r
\n" ); document.write( "\n" ); document.write( "P2 | 60 | 1/60 | 1/60x\r
\n" ); document.write( "\n" ); document.write( "P3 | 75 | 1/75 | 1/75x\r
\n" ); document.write( "\n" ); document.write( "this is my solving: \r
\n" ); document.write( "\n" ); document.write( "1/50x + 1/60x + 1/75x = 1\r
\n" ); document.write( "\n" ); document.write( "simplified:\r
\n" ); document.write( "\n" ); document.write( "6/300x + 5/300x + 4/300x = 1\r
\n" ); document.write( "\n" ); document.write( "My final answer was 25. When I checked online it said I was wrong. I would like to know where my mistake is.\r
\n" ); document.write( "\n" ); document.write( "Thanks for taking the time to help me! \n" ); document.write( "

Algebra.Com's Answer #669176 by jorel555(1290) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let n be the amount of time taken to fill the tank. If all 3 pumps are going at the same time, then:
\n" ); document.write( "n/50 + n/60 -n/75=1 (The third pump DRAINS the tank.)
\n" ); document.write( "So:
\n" ); document.write( "6n/300 + 5n/300 - 4n/300=1
\n" ); document.write( "7n=300
\n" ); document.write( "n=300/7
\n" ); document.write( "It will take 300/7 minutes to fill the tank. ☺☺☺☺
\n" ); document.write( " \n" ); document.write( "

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