Question

A plane gets an average of 25 miles per gallon when it is traveling 500 miles per hour. The plane has 15,000 gallons of gas at the beginning of a trip and travels at an average speed of 500 miles per hour. Which of the following functions f models the number of gallons of gas remaining in the tank t hours after the trip begins?

(A) f = 15000 + (25t/500)

(B) f = 15000 - (25t/500)

(C) f = 15000 - (500t/25)

(D) f = 15000 - 25t

(E) f = 25t

Answer 1

D; f = 15,000 - 25t

Explanation:

From the question;

per gallon, the number of miles traveled is 25, given traveling speed is 500 miles per hour

So after t hours, if traveling at 500 miles per hour, the amount of fuel expended will be 25 * t = 25t gallons

So, to get the amount remaining, we subtract 25t from what we have at the start of the trip

Mathematically, we have this as;

f = 15,000 - 25t