Question

Sara drives 96 miles on 3.2 gallons of gas. She uses this information to calculate how many miles per gallon she can drive. Using this result, how many miles can Sara drive on 12.5 gallons of gas?

Answer 1

You can set up a proportion.
Let x represent the number of miles Sara can drive on 12.5 gal of gas.
96 mi / 3.2 = x / 12.5 gal
Now cross multiply.
96 * 12.5 = 3.2x
1200 = 3.2x
x = 375
375 miles

Answer 2

Hi

96 miles ⇒ 3.2 gallons
x miles ⇒ 12.5 gallons

3.2x = 96·(12.5)
3.2x = 1,200
x = 1,200/3.2
x = 12,000/32
x = 375 miles

or

96/3.2 = 960/32 = 30 miles/gallon

1 gallon ⇒ 30 miles
12.5 gallons ⇒ x miles

x = 30·(12.5)
x = 375 miles

Answer: 375 miles