Find the next number in the sequence

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

A Doctor always sneezes before the rain. Doctor sneezes, Will it rain?

There are a number of books on a shelf. If one book is the 4th from the left and 6th from the right, how many books are on the shelf?

What part of the chicken has the most feathers?

One night, a man runs away from home. He turns left and keeps running. After some time he turns left again and keeps running. Later, he turns left one more time and runs back home—but when he gets home, he finds a man in a mask. Who was the man in the mask?

A shepherd had 18 sheep, out of which, all but ten died.

Can you tell us how many sheep was he left with?

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 ?

As easy as you can get into me, it is as hard to get out of me.

Do you know what I am?

When you stop to look, you can always see me. But if you try to touch me, you can never feel me. Although you walk towards me, I remain the same distance from you. What am I?

Is the statement valid that it does not matter how much older a sibling is, eventually the younger one will be half as old as the older one?