butterfly flies 8.7 kilometers per hour, and a bee flies 2.4 times faster than the butterfly. How many kilometers does this bee fly per hour?
一只蝴蝶每小时飞行8.7千米，一只蜜蜂的飞行速度是这只蝴蝶的2.4倍．这只蜜蜂每小时飞行多少千米？
<gadget id="calculator">8.7 * 2.4</gadget>
<output>20.88</output>

<result>20.88</result>