The ratio of the two numbers of A and B is 3:5, and the number of A is 24 less than the number of B. What is the number of A?
甲乙两数的比是3：5，甲数比乙数少24，甲数是多少．
<gadget id="calculator">5 - 3</gadget>
<output>2</output>

<gadget id="calculator">24 / 2</gadget>
<output>12</output>

<gadget id="calculator">12 * 3</gadget>
<output>36</output>

<result>36</result>