In October this year, Li Ming's household electricity was 131 degrees, and Wang Qiang's household electricity was 120 degrees. Wang Qiang's family paid 5.5 yuan less for electricity. How much is the average per unit of electricity?
今年10月份李明家用电131度，王强家用电120度，王强家少缴电费5.5元．平均每度电多少元？
<gadget id="calculator">131 - 120</gadget>
<output>11</output>

<gadget id="calculator">5.5 / 11</gadget>
<output>0.5</output>

<result>0.5</result>