The cafeteria brings in a batch of coal, 50 tons are used for the first time, and 70 tons are used for the second time, and (1/4) of this batch of coal is used up twice. How many tons is this batch of coal?
食堂运进一批煤，第一次用去50吨，第二次用去70吨，两次正好用去了这批煤的(1/4)．这批煤有多少吨？
<gadget id="calculator">50 + 70</gadget>
<output>120</output>

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

<gadget id="calculator">120 / (1/4)</gadget>
<output>480</output>

<result>480</result>