每日一题

Mathematics

The maximum legal height of a flatbed tractor trailer in a certain state in the US is 13.5 feet above the ground. The floor of a certain trailer is 5 feet above the ground. The remaining height is for cargo. If the cargo on this trailer consists of c layers of wood, each 1.5 feet high, which of the following inequalities can be used to determine the number of layers of wood that can be in compliance with the law?

A.5-1.5c≤13.5
B.5+1.5c≥13.5
C.5+1.5c≤13.5
D.5-1.5c≥13.5

答案和解析

答案：C

解析：

Option C is correct. The height of c layers of wood is 1.5c feet and the height of the trailer is 5 feet. Therefore, the height, in feet, of the trailer plus the cargo is 5+1.5c and the height of the trailer plus the cargo must be less than or equal to 13.5 feet.