The average of the three numbers A, B, and C is 12. The ratio of A, B, and C is 2:3:4. What is the number of C?
甲、乙、丙三个数的平均数是12，甲、乙、丙的比是2：3：4，丙数等于多少．
<gadget id="calculator">2 + 3 + 4</gadget>
<output>9</output>

<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">12 * 3 * (4/9)</gadget>
<output>16</output>

<result>16</result>