The average of the two numbers A and B is 5, and the ratio of these two numbers is 5:3, so what is the number B?
甲、乙两数的平均数是5，这两个数的比是5：3，那么乙数是多少．
<gadget id="calculator">5 + 3</gadget>
<output>8</output>

<gadget id="calculator">2 / 8</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">5 * (1/4)</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">3 * (5/4)</gadget>
<output>15/4 = around 3.75</output>

<result>15/4 = around 3.75</result>