The school bought 36 volleyballs, 6 more than three times the number of footballs. How many footballs did the school buy?
学校买了排球36个，比足球个数的3倍还多6个，学校买了多少个足球？
<gadget id="calculator">36 - 6</gadget>
<output>30</output>

<gadget id="calculator">30 / 3</gadget>
<output>10</output>

<result>10</result>