There are 28 soccer balls in the school, 15 fewer volleyballs than footballs, 6 more volleyballs than basketballs, how many basketballs are there?
学校有足球28只，排球比足球的3倍少15只，排球比篮球多6只，篮球有多少只？
<gadget id="calculator">28 * 3</gadget>
<output>84</output>

<gadget id="calculator">84 - 15 - 6</gadget>
<output>63</output>

<result>63</result>