The railway department urgently dispatched a batch of disaster relief materials. The first shipment (1/50) was 60 tons more than the total, and the second shipment (1/4) was 40 tons less, leaving 310 tons. This batch of disaster relief materials How many tons in total?
铁路部门紧急调运一批救灾物质，第一次运走总数的(1/50)多60吨，第二次运走总数的(1/4)少40吨，还剩310吨，这批救灾物资共多少吨？
<gadget id="calculator">310 - 40</gadget>
<output>270</output>

<gadget id="calculator">60 + 270</gadget>
<output>330</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/5) - (1/4)</gadget>
<output>11/20 = around 0.55</output>

<gadget id="calculator">330 / (11/20)</gadget>
<output>600</output>

<result>600</result>