Uncle Wang rides a bicycle from A to B. If he travels 12 kilometers per hour and arrives in 5 hours, if he wants to arrive 1 hour earlier, how many kilometers does he need to travel per hour?
王叔叔骑自行车从甲地到乙地，如果每小时行12千米，5小时到达，如果想提前1小时到达，每小时需要行多少千米？
<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">5 / 4</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">12 * (5/4)</gadget>
<output>15</output>

<result>15</result>