Xiao Ming and Xiao Hong rode bicycles from the same place to opposite directions. After 0.5 hours, they are 12.5 kilometers apart. Xiao Ming travels 12 kilometers per hour, how many kilometers per hour does Xiao Hong travel?
小明和小红骑自行车从同一地点向相反的方向骑去．0.5小时后它们相距12.5千米．小明每小时行12千米，小红每小时行多少千米？
<gadget id="calculator">12 * 0.5</gadget>
<output>6</output>

<gadget id="calculator">12.5 - 6</gadget>
<output>6.5</output>

<gadget id="calculator">6.5 / 0.5</gadget>
<output>13</output>

<result>13</result>