(3/10) of a number is 18 less than its (3/4). Find this number.
一个数的(3/10)比它的(3/4)少18．求这个数．
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">(3/4) - (3/10)</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">18 / (9/20)</gadget>
<output>40</output>

<result>40</result>