As per the problem
Brett currently spends $160 each month on gas.
Brett current car is able to travel 30 miles per gallon of gas.
New car is able to travel 40 miles per gallon of gas.
Assuming the price of gas stays the same.
It mean that the cost when car is able to travel 40 miles per gallon of gas can be given by
[tex] Cost=\frac{30}{40}*160
\ dollar \\
\\
Cost= 30*4 \ dollar\\
\\
Cost=120 \ dollar \\ [/tex]
Spend on gas each month with the new car=$120.
