这个 问题 太 简单 了 ，连 三岁 小孩 都 知道 。
This question is so easy that even a three-year-old kid knows the answer.
For me, I think that removing 都 from this sentence still make sense.
What exactly this 都 is meaning here?
I used the dictionary and got the meanings as all, both, entirely .
So I think that adopting entirely is the best but I can't have a confidence.