Question 1037630
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12 children working 8 hours a day can clean up their school in 5 days, then 8 children working 19 hours a day will clean the school in how many days.
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The equation is 

12*5*8 = 8*x*19.

Find x from this equation.


The equation says that he number of man-hours (children-hours) is the same in both cases.


The problem is so simple and the solution is so obvious that the general theory is not required.
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