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

John is the son of Jacob.
So,
Jacob is the_____of John's father?

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

What type of tree can I carry in my hand?

I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?

If eleven plus two equals one, what does nine plus five equal?

Mr Red Lives in the red house.
Mr Green Lives in the greenhouse.
Mr Yellow Lives in the yellow house.

Who lives in the Whitehouse?

There is so small cabin inside a deep forest.
All the forest burned out to worst possible but the inside of the cabin is still the same.
However all the person inside the cabin die.

How come ?

13 decks of cards have been mixed. What is the minimum number of cards that must be taken out from the above-mixed cards to guarantee at least one 'four of a kind?

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 ?