A truck transported 360 pieces of glass instruments, each with a shipping fee of 5 yuan. If one piece of equipment was damaged, not only the shipping fee would not be paid, but also 50 yuan would be paid. As a result, the driver only received a shipping fee of 1,250 yuan. How many instruments were damaged?
一辆卡车装运玻璃仪器360个，每个运费5元，若损坏一个仪器不但不给运费，还要赔50元，结果司机只收到运费1250元，问损坏了几个仪器？
<gadget id="calculator">360 * 5</gadget>
<output>1_800</output>

<gadget id="calculator">1_800 - 1_250</gadget>
<output>550</output>

<gadget id="calculator">5 + 50</gadget>
<output>55</output>

<gadget id="calculator">550 / 55</gadget>
<output>10</output>

<result>10</result>