The young pioneers cut grass for the farm. The first group of 7 people cut 13 kilograms on average, and the second group of 5 people cut 25 kilograms on average. How many kilograms of grass was mowed by each person on average?
少先队员为饲养场割草，第一组7人，平均每人割13千克，第二组5人，平均每人割25千克，平均每人割草多少千克？
<gadget id="calculator">13 * 7</gadget>
<output>91</output>

<gadget id="calculator">5 * 25</gadget>
<output>125</output>

<gadget id="calculator">91 + 125</gadget>
<output>216</output>

<gadget id="calculator">7 + 5</gadget>
<output>12</output>

<gadget id="calculator">216 / 12</gadget>
<output>18</output>

<result>18</result>