The sum of father and mother's age this year is 78 years old. 6 years later, father is 4 years older than mother. How old is dad this year?
爸爸、妈妈今年的年龄和是78岁．6年后，爸爸比妈妈大4岁．爸爸今年多少岁．
<gadget id="calculator">78 + 4</gadget>
<output>82</output>

<gadget id="calculator">82 / 2</gadget>
<output>41</output>

<result>41</result>