Question

Jack estimates that the cost per mile, in dollars, for operating a certain truck is between 15% and 21% of the number of miles driven. This is shown by the system of inequalities below, where x represents the number of miles driven and y represents the cost of operating the truck.

y ≥ 0.15x


y ≤ 0.21x


Based on this information, which statement is true?


A) If Jack drives over 15 miles, it will cost 15 · 0.15 to operate the truck.

B) If Jack drives less than 21 miles, it will cost 21 · 0.21 to operate the truck.

C) If Jack drives the truck 100 miles, it will cost either $15 or $21.

D) If Jack drives 200 miles, it will cost anywhere between $30 and $42.

Answer 1

D) If Jack drives 200 miles, it will cost anywhere between $30 and $42

Explanation:

The cost is said to be a range of possibilities. The first three answer choices seem to assume the cost is at one extreme or the other. They incorrectly interpret the statement of cost.