In the first quarter of this year (January, February, and March), Mingming’s family paid a total of 138 yuan for water, of which 48 yuan was paid in March. How much was the average monthly payment in the first two months?
明明家今年第一季度(1月、2月、3月)共交水费138元，其中三月份交水费48元，前两个月平均每个月交了多少钱？
<gadget id="calculator">138 - 48</gadget>
<output>90</output>

<gadget id="calculator">90 / 2</gadget>
<output>45</output>

<result>45</result>