Answer:
The car can travel 147 miles on 7 gallons of gas
Explanation:
A car traveled on 3 gallons of gas = 63 miles 
car traveled on 1 gallons of gas = = 21 miles 
Therefore, car traveled on 7 gallons of gas = 21 × 7 = 147 miles. 
The proportion will be = × 7 = × 7 
The car can travel 147 miles on 7 gallons of gas.