40% of a number is exactly equal to half of 24. Find this number.
一个数的40%正好与24的一半相等，求这个数．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(1/2) / (2/5)</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">24 * (5/4)</gadget>
<output>30</output>

<result>30</result>