This year, the ages of Xiao Ming, his father, and his mother are 8, 32, and 30 years old, respectively. How many years later, the age of father and mother is four times that of Xiaoming.
今年，小明和爸爸、妈妈的年龄分别是8岁、32岁、30岁．多少年后，爸爸、妈妈的年龄和是小明的4倍．
<gadget id="calculator">8 * 4</gadget>
<output>32</output>

<gadget id="calculator">30 - 32</gadget>
<output>-2</output>

<gadget id="calculator">32 + (-2)</gadget>
<output>30</output>

<gadget id="calculator">4 - 2</gadget>
<output>2</output>

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

<result>15</result>