The average of the three numbers A, B, and C is 30, and the ratio of the three numbers A, B, and C is 3:2:1. How much is armor.
甲、乙、丙三个数的平均数是30，甲、乙、丙三个数的比是3：2：1．甲是多少．
<gadget id="calculator">3 / 6</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">30 * 3 * (1/2)</gadget>
<output>45</output>

<result>45</result>