There is a family of three, the father is 3 years older than the mother, the combined age of the whole family is exactly 58 years old this year, and the combined age of the whole family is exactly 45 years old 5 years ago. How old is the child this year?
有一家三口，爸爸比妈妈大3岁，他们全家今年的年龄加起来正好是58岁，而5年前他们全家人年龄加起来刚好是45岁．小孩子今年多少岁．
<gadget id="calculator">5 * 3</gadget>
<output>15</output>

<gadget id="calculator">58 - 15</gadget>
<output>43</output>

<gadget id="calculator">45 - 43</gadget>
<output>2</output>

<gadget id="calculator">5 - 2</gadget>
<output>3</output>

<result>3</result>