Answer:
$50.58
Step-by-step explanation:
Sine Charles's old car only gets 20 miles per gallon and the round trip will be 350 miles, he will use 350/20 = 17.5 gallons.
Since each gallon costs $2.89, he will spend in gasoline a total of = 17.5 gallons x $2.89 per gallon = $50.58
If he drove the other car he would have spent 10 gallons x $2.89 = $28.90 in gasoline