2.5 times a number is 30 more than itself, what is this number?
一个数的2.5倍比它本身多30，这个数是多少？
<gadget id="calculator">2.5 - 1</gadget>
<output>1.5</output>

<gadget id="calculator">30 / 1.5</gadget>
<output>20</output>

<result>20</result>