document.write( "Question 121668: One person can do a certain job in twenty-one minutes, and another person can do the same job in twenty-eight minutes. How many minutes will it take them to do the job altogether? \n" ); document.write( "
Algebra.Com's Answer #89319 by checkley71(8403)\"\" \"About 
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21*28/(21+28)=588/49=12 MINUTES TO COMPLETE THE JOB WORKING TOGETHER. \n" ); document.write( "
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