Given : Andre drove 200 Miles using 9 Gallons of Gas
⇒ Andre drives 1 Mile using [tex][\frac{9}{200}]\;Gallons\;of\;Gas[/tex]
⇒ Andre drives (420 × 1 Mile) using [tex][\frac{420\times9}{200}]\;Gallons\;of\;Gas[/tex]
⇒ Andre drives 420 Miles using 18.9 Gallons of Gas