Answer
To travel $820$ miles, we would need $26.4$ gallons of fuel.
Work Step by Step
Let the gallons of fuel required be x. Then:
$18$ gal of fuel = $560$ miles.
$x$ gal of fuel= $820$ miles
Then we get the ratio:
$\dfrac{18~g}{560~mi}=\dfrac{x}{820~mi}$
By cross multiplication, we get
$(820*18)=(x*560)$
$x=(820*18)/560$
$x=26.4$ gallons.
Therefore, to travel 820 miles, we would require 26.4 gallons of fuel.
