Hongxing Furniture Factory plans to produce 300 sets of sofas in the first half of the year. 50 sets were produced in January, 30 sets were produced in February, 55 sets were produced in March, and the remaining three months were completed. How many sets will be produced on average each month in the next three months to complete the task?
红星家具厂计划上半年生产300套沙发．一月生产了50套，二月生产了30套，三月生产了55套，剩下的三个月完成．后三个月平均每月生产多少套才能完成任务？
<gadget id="calculator">300 - 50 - 30 - 55</gadget>
<output>165</output>

<gadget id="calculator">165 / 3</gadget>
<output>55</output>

<result>55</result>