document.write( "Question 342502: It takes a boy 30 minutes to mow the lawn, but his sister can mow it in 20 minutes. How long would it take them to mow the lawn if they worked together, using two lawn mowers? \n" ); document.write( "
Algebra.Com's Answer #245181 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.\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( "time periods.\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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