Question

A truck can travel 140 miles on 7 1/2 gallons of gas. How far can the truck travel with 16 gallons of gas ?

Answer 1

298.6 miles 

you can solve this by setting up a proportion

ie. 140 miles over 7.5 gallons set it equal to X miles over 16 gallons. 
Cross multiply to find 7.5x=2240 and divide by 7.5 to get 298.6 miles on 16 gallons of gas 

hope this helped!