Question 339447
If Tom can do a job in 2 days, Mike can do the job in 4 days, and Ann can do it in 6 days,
 how long will it take them if they do it together?
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Let t = time required when they all work together
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Let the completed job = 1
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Each will do a fraction of the job, the three fractions add up to 1; therefore:
{{{t/2}}} + {{{t/4}}} + {{{t/6}}} = 1
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Multiply the equation by 12, results
6t = 3t + 2t = 12
:
11t = 12
t = {{{12/11}}}
t = 1{{{1/11}}} hr or 1 hr + {{{1/11}}}*60 = 1 hr 5.45 minutes
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What is the square of 25/9? 
Just square the numerator and the denominator: 625/81
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In case you meant the square root: that's 5/3