A Company Handles an Apartment Building with 50 Units

Multiple Choice

A company handles an apartment building with 50 units. Experience has shown that if the rent for each of the units is $380 per month, then all of the units will be filled; however, one unit will become vacant for each $30 increase in the monthly rate. If x represents the number of $30 increases, express the revenue R from the building as a function of x. ​

A) ​R(x) = 380+30x
B) R(x) = (380+30x) (50-x)
C) R(x) = 50(380+30x)
D) R(x) = 30(380-30x) (50-x)
E) R(x) = 50(380-30x)