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Time and Work Equations

by Ashish
(Ranchi,Jharkhand,India)











































a certai job was assigned to a group of men to do in 20 days. but 12 men did not turn up for the job and the remaning men did the job in32 days.the original number of men in the group was?

Comments for Time and Work Equations

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Jul 09, 2011
Time and Work Equations
by: Staff


The question:

a certai job was assigned to a group of men to do in 20 days. but 12 men did not turn up for the job and the remaning men did the job in 32 days.the original number of men in the group was?


The answer:

x = number of men in the original group

The total number of man-days required to complete the job will not change, regardless of the number of men working on the job.

man-days for partial crew to complete job = man-days for assigned crew (original group)


set up equation

(x men - 12 men) * (32 days) = (x men) * (20 days)

(x - 12) * (32) = (x) * (20)


Solve for x

Eliminate the parentheses on the left side of the equation using the distributive law

32*x - 32*12 = x*20

32x - 384 = 20x


Add 384 to each side of the equation to eliminate the 384 from the left side of the equation

32x - 384 + 384 = 20x + 384

32x + 0 = 20x + 384

32x = 20x + 384


Subtract 20x from each side of the equation to eliminate the 20x from the right side of the equation

32x - 20x = 20x - 20x + 384

12x = 20x - 20x + 384

12x = 0 + 384


Divide each side of the equation by 12 to eliminate the 12 on the left side of the equation.

12x = 384

12x/12 = 384/12

12x/12 = 32

x*(12/12) = 32

x*(1) = 32

x = 32


the final answer is: the size of the original group was 32 men


Thanks for writing.

Staff
www.solving-math-problems.com



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