Mark's car breaks down and he needs to get a new radiator.  The cost for a new radiator is $400 but he goes to get it at a junk shop and gets it for 80% off.  He then hires a mechanic to install it and it takes 3 hours at $50 an hour.  How much did he pay?
The discount on the radiator was 400*.8=$
<gadget id="calculator">400*.8</gadget>
<output>320</output>
320.
So he paid 400-320=$
<gadget id="calculator">400-320</gadget>
<output>80</output>
80.
The mechanic charges 3*50=$
<gadget id="calculator">3*50</gadget>
<output>150</output>
150.
So in total he paid 80+150=$
<gadget id="calculator">80+150</gadget>
<output>230</output>
230.

<result>230</result>