After subtracting 20% of a number, it is equal to (1/3) of 120. Find this number.
一个数减去它的20%后，等于120的(1/3)，求这个数．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

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

<gadget id="calculator">120 * (5/12)</gadget>
<output>50</output>

<result>50</result>