There are 6 footballs in the sporting goods store, and the number of basketballs is three times that of footballs. How many basketballs are there?
体育用品店里有足球6个，篮球的个数是足球的3倍，篮球有多少个．
<gadget id="calculator">6 * 3</gadget>
<output>18</output>

<result>18</result>