A butterfly flies 15.6 km in 2 hours, and the flying speed of a bee is 2.4 times that of a butterfly. What is the speed of the bee?
一只蝴蝶2小时飞行15.6km，蜜蜂的飞行速度是蝴蝶的2.4倍．算一算蜜蜂的飞行速度是多少？
<gadget id="calculator">15.6 / 2</gadget>
<output>7.8</output>

<gadget id="calculator">7.8 * 2.4</gadget>
<output>18.72</output>

<result>18.72</result>