A group of 10 coworkers has agreed to equally share the cost of a gift

Question

A group of 10 coworkers has agreed to equally share the cost of a gift costing d dollars. If w of the coworkers later decide not to contribute, how much more must each of the remaining coworkers pay toward the gift?

A.  \frac{d}{10 - w}

B.  \frac{d(w - 10)}{10w}

C.  \frac{dw}{10(10 - w)}

D.  \frac{10-w}{d}

E.  \frac{10dw}{10 -w}

Archit3110 · Answer

d/10

new amount to be paid :
d/10-w
 
more amount to be paid d/10-w - d/10
i.e  \frac{dw}{10(10 - w)}

IMO C

ScottTargetTestPrep · Answer

The original amount paid by each coworker was d/10. After w of the coworkers did not pay for the gift, the new amount that each coworker had to pay became d/(10 - w). Thus, the additional amount that each coworker now had to pay was:

d/(10 - w) - d/10

10d/  - d(10 - w)/

(10d - 10d + wd)/

wd/

Answer: C

0Lucky0 · Answer

chetan2u , If possible, answer this question please. I answered A, I don't understand why we need to subtract d/10 from A.

chetan2u · Answer

0Lucky0 , a very easy way in these questions is to substitute values for variables 
Let w be 2 and d be 100.
So, each had to pay 100/10 or 10$
But two didn’t pay so 20$ is to be paid by remaining 10-2 or 8. 
Extra each of these 8 had to pay = 20/8 = 2.5$

Substitute and see where you get 2.5 as answer. 
C.  \frac{dw}{10(10 - w)} =  \frac{100*2}{10(10 - 2)} =2.5

Now why we are subtracting d/10 from d/(10-w)
d/(10-w) is what the remaining actually paid while d/10 is what each one would have paid initially. 
We are looking at how MUCH MORE each had to pay. So you subtract what they were to pay from what they eventually paid.

A group of 10 coworkers has agreed to equally share the cost of a gift

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A group of 10 coworkers has agreed to equally share the cost of a gift

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