The average of the two numbers A and B is 100, and the ratio of A and B is 5:3. What is A's number?
甲、乙两数的平均数是100，甲乙两数之比为5：3，甲数是多少．
<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">100 * (1/4) * 5</gadget>
<output>125</output>

<result>125</result>