GRE Question of the Day (September 21st)

A manufacturer can save X dollars per unit in production costs by overproducing in certain seasons. If storage costs for the excess are y dollars per unit per day ( X > Y), which of the following expresses the maximum number of days that n excess units can be stored before the storage costs exceed the savings on the excess units?

A) \({x - y}\)
B) \({(x - y)n}\)
C) \({\frac{{x}}{{y}}}\)
D) \({\frac{{xn}}{{y}}}\)
E) \({\frac{{x}}{{yn}}}\)