In the question it is already given the amount of actual gasoline and money consumed before the fuel efficiency gets increased by 25%
Gasoline consumption before the increase in fuel efficiency = 25 gallons per week
Gasoline saved after the increase in fuel efficiency = [25 (25/100)] gallons per week
= 6.25 gallons per week
So every week 6.25 gallons of gasoline can be saved after increasing the efficiency of the automobile by 25%.
Then
The amount of money saved against the 6.25 gallons of gasoline saved = (6.25 2) dollars
= 12.50 dollars
The amount of money saved is $12.50 per week.
