A taxi truck delivers 600 thermos bottles to a shopping mall. The two parties agreed that the shipping fee for each thermos bottle was 0.40 yuan. If one was broken, not only would the shipping fee not be paid for this one, but a compensation of 11.50 yuan would be required. How many thermoses broke in transit?
一辆出租货车为某商场运送600个热水瓶．双方约定，每个热水瓶运费0.40元，如果打碎一个，这一个不但不给运费，还要赔偿11.50元，结果货车司机共得运费192.40元．运送过程中打破了几个热水瓶？
<gadget id="calculator">0.4 * 600</gadget>
<output>240</output>

<gadget id="calculator">240 - 192.4</gadget>
<output>47.6</output>

<gadget id="calculator">0.4 + 11.5</gadget>
<output>11.9</output>

<gadget id="calculator">47.6 / 11.9</gadget>
<output>4</output>

<result>4</result>