30 minus 3 times a number, the difference is equal to 6 times 3.2, find this number.
30减去一个数的3倍，差等于3.2的6倍，求这个数．
<gadget id="calculator">3.2 * 6</gadget>
<output>19.2</output>

<gadget id="calculator">30 - 19.2</gadget>
<output>10.8</output>

<gadget id="calculator">10.8 / 3</gadget>
<output>3.6</output>

<result>3.6</result>