John rents a car to visit his family.  It cost $150 to rent the car.  He also had to buy 8 gallons of gas to fill it up and gas is $3.50 per gallon.  The final expense is $.50 per mile.  If he drove 320 miles how much did it cost?
The gas cost 8*3.5=$
<gadget id="calculator">8*3.5</gadget>
<output>28</output>
28.
The mileage expenses cost 320*.5=$
<gadget id="calculator">320*.5</gadget>
<output>160</output>
160.
So in total he paid 150+28+160=$
<gadget id="calculator">150+28+160</gadget>
<output>338</output>
338.

<result>338</result>