Question

At the beginning of the day, the owner of a restaraunt opens a new case of take-out boxes. One case holds 500 take-out boxes. He uses an average of 35 take-out boxes each day. Based on his average usage, which expression represents the number of take-out boxes that remain (d) days after the new case of boxes is opened?
A: 500 - 35d
B: 500 + 35d
C: 500d - 35
D: 500d + 35