Divide 9 times a certain number by 20 0.75, the quotient is 0.3, find a certain number.
某数的9倍除以20个0.75，商是0.3，求某数．
<gadget id="calculator">0.3 * 0.75 * 20</gadget>
<output>4.5</output>

<gadget id="calculator">4.5 / 9</gadget>
<output>0.5</output>

<result>0.5</result>