The R students in a class agree to contribute equally to buy their teacher a birthday present that costs y dollars. If

[BTGmoderatorDC]

The R students in a class agree to contribute equally to buy their teacher a birthday present that costs y dollars. If x of the students later fail to contribute their share, which of the following represents the additional number of dollars that each of the remaining students must contribute in order to pay for the present?

(A) y/R
(B) y/(R-x)
(C) xy/(R-x)
(D) xy/(R(R-x))
(E) y/(R(R-x))


OA D

Source: Princeton Review

[Scott@TargetTestPrep]

The R students in a class agree to contribute equally to buy their teacher a birthday present that costs y dollars. If x of the students later fail to contribute their share, which of the following represents the additional number of dollars that each of the remaining students must contribute in order to pay for the present?

(A) y/R
(B) y/(R-x)
(C) xy/(R-x)
(D) xy/(R(R-x))
(E) y/(R(R-x))


OA D

Solution:

The original amount of money paid by each student is y/R

The new amount of money paid by each student is y/(R - x)

The difference is:

y/(R - x) - y/R

yR/[R(R-x)] - y(R-x)/[R(R-x)]

(yR- yR + yx)/[R(R-x)]

yx/[R(R-x)]

Answer: D