8 times a number plus 40% of 20, the sum is 10. Find this number.
一个数的8倍加上20的40%，和是10．求这个数．
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">20 * (2/5)</gadget>
<output>8</output>

<gadget id="calculator">10 - 8</gadget>
<output>2</output>

<gadget id="calculator">2 / 8</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>