Question

Scott has a car that can travel 25 miles on one gallon of gas. He is buying a new car that can travel 32 miles on one gallon of gas. How much gas will he save over the course of 100 miles after buying his new car?
A.
7 gallons

B.
0.875 gallons

C.
0.009 gallons

D.
1.28 gallons

Answer 1

The answer is B. .875 gallons

25/1=100/x
25x=100
x=100/25=4 gallons

32/1=100/x
32x=100
x=100/32
x=3.125 gallons 

4-3.125=0.875 gallons

Answer 2

We divide 100 miles by each car...100/25 = 4 gallons on that car
                                                     100/32 = 3.125 gallons on this one
subtract the two answers 4 - 3.125 and we get a savings of .875 gallons on 100 miles.