There are 2 tons of coal, (1/3) of the total amount is removed for the first time, and (2/5) of the total amount is removed for the second time, what fraction of this pile of coal is left?
有2吨煤，第一次运走总数的(1/3)，第二次运走总数的(2/5)，还剩下这堆煤的几分之几？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

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

<gadget id="calculator">1 - (1/3) - (2/5)</gadget>
<output>4/15 = around 0.266667</output>

<result>4/15 = around 0.266667</result>