The average of the two numbers A and B is 5, and the ratio of the two numbers A and B is 2:3, so what is the number B?
甲、乙两数的平均数是5，甲乙两个数的比是2：3，那么乙数是多少．
<gadget id="calculator">2 + 3</gadget>
<output>5</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">3 * 5 * (2/5)</gadget>
<output>6</output>

<result>6</result>