A number (2/7) is 30 less than 2 times of 3.6 Find this number.
一个数的(2/7)比3.6的2倍少30求这个数．
<gadget id="calculator">3.6 * 2</gadget>
<output>7.2</output>

<gadget id="calculator">7.2 - 3</gadget>
<output>4.2</output>

<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">4.2 / (2/7)</gadget>
<output>14.7</output>

<result>14.7</result>