Wu Tian asked his grandfather how old he was this year, and his grandfather thought about it and said humorously: "In three years, my age will be six times your age in three years." Wu Tian is 11 years old this year, so how old is grandpa this year?
吴天问外公今年几岁，外公想了想幽默的说："三年后我的年龄是三年后你的年龄的6倍．"吴天今年11岁，那么外公今年几岁？
<gadget id="calculator">11 + 3</gadget>
<output>14</output>

<gadget id="calculator">14 * 6</gadget>
<output>84</output>

<gadget id="calculator">84 - 3</gadget>
<output>81</output>

<result>81</result>