The school bought 15 footballs and 15 volleyballs each, 40 yuan for each football, and 25 yuan for each volleyball. How much more does it cost to buy footballs than volleyballs?
学校买了足球和排球各15只，每只足球40元，每只排球25元，买足球的钱比排球的钱多多少元？
<gadget id="calculator">40 - 25</gadget>
<output>15</output>

<gadget id="calculator">15 * 15</gadget>
<output>225</output>

<result>225</result>