A batch of goods was shipped three times, 28% of this batch was shipped for the first time, 30% of this batch was shipped for the second time, and the rest was shipped for the third time. It is known that the first two shipments totaled 87% tons, how many tons is the third shipment?
一批货物分三次运完，第一次运了这批货物的28%，第二次运走了这批货物的30%，其余的第三次运完，已知前两次共运货87吨，第三次运货物多少吨？
<gadget id="calculator">28 / 100</gadget>
<output>7/25 = around 0.28</output>

<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">(7/25) + (3/10)</gadget>
<output>29/50 = around 0.58</output>

<gadget id="calculator">87 / (29/50)</gadget>
<output>150</output>

<gadget id="calculator">1 - (7/25) - (3/10)</gadget>
<output>21/50 = around 0.42</output>

<gadget id="calculator">150 * (21/50)</gadget>
<output>63</output>

<result>63</result>