The transport team transported a batch of building materials to the construction site. On the first day, 30% of the total was transported, on the second day, 40% of the total was transported, and on the third day, the last 60 tons were transported. How many tons are there in total for this batch of building materials?
运输队向工地运送一批建筑材料，第一天运的是总数的30%，第二天运的是总数的40%，第三天运完了最后的60吨．这批建筑材料共有多少吨？
<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (3/10) - (2/5)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">60 / (3/10)</gadget>
<output>200</output>

<result>200</result>