The average of the three numbers A, B, and C is 12, and their ratio is 1:2:3. What is the number of C?
甲乙丙三数的平均数为12，它们的比是1：2：3，丙数是多少．
<gadget id="calculator">3 / 9</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">36 * (1/3)</gadget>
<output>12</output>

<result>12</result>