It is known that A: B=3:5, A is 24 smaller than B, what is the number of A?
已知甲：乙=3：5，甲比乙小24，求甲数是多少？
<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>