BarryLi wrote:Each year's increase or decrease in the trade deficit (merchandise imports greater than exports) is calculated in relation to the previous year's. In 1976, imports of private vehicles were 10 percent higher than in 1975, while imports of vehicles including commercial vans was 15 percent higher than in 1975. That 15 percent increase was one and a half times the increase recorded in 1975.

If the information above is accurate, which of the following must be true?

A) In 1976, the increase, if any, of commercial vehicle imports was smaller than the increase in imports of private vehicles.

B) In 1976, the increase, if any, of commercial vehicle imports was greater than the increase in imports of private vehicles.

C) In 1975, more commercial vehicles were imported than private vehicles.

D) In 1975, more private vehicles were imported than commercial vehicles.

E) The average number of private vehicles imported in 1975 declined.

First, the increase in imports of both types of vehicles was one and a half times greater in 1976 than in 1975. That means that there was a 10 percent increase in the import of both types of vehicles in 1975. Likewise, if the increase for 1976 of private vehicles was 10 percent, then the increase in 1975 was 6.7 percent. Therefore, the different in import increases for both types of vehicles between 1975 and 1976 is 5 percent and for private vehicles, 3.3 percent. The relative increase in both types of vehicles was 5 percent, including the relative increase in private vehicles of 3.3 percent. Therefore, the residual, relative increase in commercial vehicles was 5 percent - 3.3 percent, or 1.7 percent, less than the increase in private ones. The correct answer is (A)