A pile of coal burns (4/5) tons, and the rest is (1/3) tons more than what was burned, what is the original number of tons of this pile of coal?
一堆煤，烧了(4/5)吨，剩下的比烧了的多(1/3)吨，这堆煤原来多少吨．
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

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

<gadget id="calculator">(4/5) + (1/3) + (4/5)</gadget>
<output>29/15 = around 1.933333</output>

<result>29/15 = around 1.933333</result>