A batch of coal was brought from the cafeteria. (1/4) was used for the first time, 300 tons were used for the second time, and (1/3) was left unburned. How many tons are there in this batch of coal?
食堂运来一批煤，第一次用去(1/4)，第二次用去300吨，还剩下(1/3)没有烧，这批煤共有多少吨？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/4) - (1/3)</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">300 / (5/12)</gadget>
<output>720</output>

<result>720</result>