An airplane uses approximately 5 gallons of fuel per mile flown. If the plane has 60,000 gallons of fuel at the beginning of a trip and flies at an average speed of 550 miles per hour, which of the following functions estimates the amount of remaining fuel A (t), in gallons, t hours after the trip began?

The correct answer is:

let t hours  be the time of flight . The average speed of the plane is 550 miles per hour
Step 1:- Find distance travelled in time t.
The distance travelled in time t = speed × time = 550 t (in miles )
Step 2:- Find the fuel consumed in time t .
Given the plane consumes 5 gallons of fuel every mile .
So ,the plane consumes 5 × 550 × t gallons of fuel for  550 × t miles in time t hours .
The fuel consumed in time = 5 × 550 × t = 2,750t gallons
Step 3:- calculate remaining amount of fuel A(t)
The initial amount of fuel = 60,000 gallons
The remaining fuel A(t)  = Initial fuel - fuel consumed  in time t.
A(t) = 60,000 - 2,750t (in gallons)