The shipping company shipped 50 boxes of glass instruments, and the contract stipulated that the shipping fee for each box was 20 yuan. However, if there is any damage, the damaged box will not only not be paid the shipping fee, but also pay 60 yuan. The shipping company only got 760 yuan in the end, and asked for damages How many boxes did you order?
货运公司运送50箱玻璃仪器，合同规定每箱运费20元，但如果有捐坏，被损坏的那一箱不仅不给运费，还要赔偿60元，货运公司最后只得到了760元，请求出损坏了多少箱？
<gadget id="calculator">20 * 50</gadget>
<output>1_000</output>

<gadget id="calculator">1_000 - 760</gadget>
<output>240</output>

<gadget id="calculator">60 + 20</gadget>
<output>80</output>

<gadget id="calculator">240 / 80</gadget>
<output>3</output>

<result>3</result>