Set up a ratio of miles traveled over gallons of gas used:
We know 152 miles / 5.7 gallons.
We want to find X miles / 18 gallons
So we have:
152/5.7 = X/18
Cross multiply:
(152 x 18) = 5.7X
2736 = 5.7x
Divide both sides by 5.7:
x = 2736 / 5.7
x = 480
They can drive 480 miles.
