Xiao Ming practiced cycling. From 11:00 to 13:00, he rode 12 kilometers per hour. How many kilometers did he travel during this time?
小明练习骑车，从11：00骑到13：00结束，他每小时骑行12千米，这段时间他共行多少千米千米．
<gadget id="calculator">12 * 2</gadget>
<output>24</output>

<result>24</result>