The transportation company transported 1,500 sets of glass tea sets for a factory, and the shipping fee for each set was 2 yuan. For each damaged set, not only was there no shipping fee, but a compensation fee of 78 yuan was deducted from the shipping fee. How many sets of tea sets were damaged during transportation?
运输公司为某厂运1500套玻璃茶具，每套运费2元，每损坏一套，不但没有运费，还要从运费中扣除赔偿费78元，结果运输公司实得运费2440元．运输过程中共损坏多少套茶具？
<gadget id="calculator">1_500 * 2</gadget>
<output>3_000</output>

<gadget id="calculator">3_000 - 2_440</gadget>
<output>560</output>

<gadget id="calculator">78 + 2</gadget>
<output>80</output>

<gadget id="calculator">560 / 80</gadget>
<output>7</output>

<result>7</result>