The sum of the two numbers of A and B is 24, the ratio of A to B is 3:5, what is the number of A?
甲乙两数的和是24，甲与乙的比是3：5，甲数是多少．
<gadget id="calculator">3 + 5</gadget>
<output>8</output>

<gadget id="calculator">24 / 8</gadget>
<output>3</output>

<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<result>9</result>