Thomas owns 200 books. He decides to sell them and use the money to buy records. Each book sells for $1.5. A record costs $3. If he buys 75 records, how much money does he have left over?
He makes $300 selling the books because 200 x 1.5 = 
<gadget id="calculator">200*1.5</gadget>
<output>300</output>
300.
He spends $225 on records because 75 x 3 = 
<gadget id="calculator">75*3</gadget>
<output>225</output>
225.
He has $75 left because 300 - 225 = 
<gadget id="calculator">300-225</gadget>
<output>75</output>
75.

<result>75</result>