The sum of (2/5) and 6 of a number is 30, what is this number?
一个数的(2/5)与6的和是30，这个数是多少．
<gadget id="calculator">30 - 6</gadget>
<output>24</output>

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

<gadget id="calculator">24 / (2/5)</gadget>
<output>60</output>

<result>60</result>