A watermelon weighs 5 kg, 3 apples weigh 1 kg, and a watermelon weighs the same as how many apples.
一个西瓜重5千克，3个苹果重1千克，一个西瓜和多少苹果一样重．
<gadget id="calculator">3 * 5</gadget>
<output>15</output>

<result>15</result>