document.write( "Question 608581: a tank can be filled by three pipes separaely in 20, 30, and 60 minutes respectively. In how many minutes can it be filled by the three pipes working together? \n" ); document.write( "
Algebra.Com's Answer #383307 by solver91311(24713)\"\" \"About 
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\n" ); document.write( "\n" ); document.write( "If A can do a job in x time periods, then A can do of the job in 1 time period. Likewise, if B can do the same job in y time periods, then B can do of the job in 1 time period. For this problem you will need C doing of the job in 1 time period\r
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\n" ); document.write( "\n" ); document.write( "So, working together, they can do\r
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\n" ); document.write( "\n" ); document.write( "of the job in 1 time period.\r
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\n" ); document.write( "\n" ); document.write( "Therefore, they can do the whole job in:\r
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\n" ); document.write( "\n" ); document.write( "John
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\n" ); document.write( "My calculator said it, I believe it, that settles it
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