5 years ago, my father was 30 years older than Xiao Ming, and 5 years later, my father is three times as old as Xiao Ming. How old is my father this year?
5年前爸爸比小明大30岁，5年后爸爸年龄是小明的3倍，今年爸爸多少岁．
<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">30 / 2</gadget>
<output>15</output>

<gadget id="calculator">15 * 3</gadget>
<output>45</output>

<gadget id="calculator">45 - 5</gadget>
<output>40</output>

<result>40</result>