Teacher Wang brought some money to buy sporting goods. The unit price of footballs is 35 yuan, and the unit price of basketballs is 42 yuan. If you use this money to buy footballs, you can buy 18 footballs. If you use this money to buy basketballs, how many can you buy?
王老师带了一些钱去买体育用品，足球的单价35元，篮球的单价42元，如果用这些钱买足球，正好可以买18个．如果用这些钱买篮球，能买多少个？
<gadget id="calculator">18 / 42</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">35 * (3/7)</gadget>
<output>15</output>

<result>15</result>