For a batch of goods, 40% of the goods were transported for the first time and 5 tons more, and 80% of the first time was transported for the second time. At this time, there are still 12 tons left. How many tons of this batch of goods originally?
一批货物，第一次运走了40%还多5t，第二次运的是第一次的80%，此时还剩下12t，这批货物原有多少吨？
<gadget id="calculator">5 + 4 + 12</gadget>
<output>21</output>

<gadget id="calculator">1 - 0.4 - 0.32</gadget>
<output>0.28</output>

<gadget id="calculator">21 / 0.28</gadget>
<output>75</output>

<result>75</result>