Solve the equation: x: 0.4 = 0.6: 0.3, x = how much.
解方程：x：0.4=0.6：0.3，x=多少．
<gadget id="calculator">0.4 * 0.6</gadget>
<output>0.24</output>

<gadget id="calculator">0.24 / 0.3</gadget>
<output>0.8</output>

<result>0.8</result>