The average of A, B, and two or three numbers is 90, and the ratio of the three numbers is 3:5:2. What is B?
甲、乙、两三个数的平均数是90，三个数之比是3：5：2，乙是多少．
<gadget id="calculator">3 + 5 + 2</gadget>
<output>10</output>

<gadget id="calculator">5 / 10</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">90 * 3 * (1/2)</gadget>
<output>135</output>

<result>135</result>