Find the next number in the sequence

1, 2, 6, 21, 88, __?

There was a blind man. He had four socks in his drawer either black or white. He opened it and took out two socks. Now the probability that it was a pair of white socks is 1/2.

Can you find out the probability that he had taken out a pair of black socks ?

What do you call a fish without an eye?

A plane crashed between the border of Mexico and America. Where do you bury the survivors?

I was born in a small house and I live in it all alone. No windows and no doors have been assigned to my house. The only way I can go out is by breaking through the walls of my house.

Who am I?

I speak without a mouth, and hear without ears. I have no-body, but I come alive with the wind. What am I?

Can you arrange four 9's and use at most 2 math symbols, to make the total 100?

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

I always drive my customer away.

Who am I?

What is common among 11, 69, and 88?