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?

Andrew sees a very rare bird named "Ruppell's vulture". Soon Andrew was dead. Can you explain the mystery, Mr. Sherlock?

A Scientist was fifty years old in the year 2000 but he was forty years old in the year 2010. How can this be possible?

PS: It has a logical answer.

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

What word is pronounced the same if you take away four of its five letters?

I have cities, but no houses. I have mountains, but no trees. I have water, but no fish. What am I?

A newspaper is supposed to have 60 pages.Pages 14 and 21 are missing from the newspaper.

Can you tell me , Which other pages won't be there as well ?

When monkey rotate the gear, which mark will be hit 1 or 2 ?

I cannot talk, but I always reply when spoken to. What am I?

Keyboard words are not in alphabetical order, Why?