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) \(\dfrac{y}{R}\)
(B) \(\dfrac{y}{R-x}\)
(C) \(\dfrac{xy}{R-x}\)
(D) \(\dfrac{xy}{R(R-x)}\)
(E) \(\dfrac{y}{R(R-x)}\)

Answer: D

Source: Princeton Review