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

What has many teeth, but cannot bite?

What's the best place to go shopping in the ocean?

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

The day after tomorrow will be three days before Tuesday. Can you find out what is today?

Can you place six X (crosses) in below board without making three in a row in any way ?

French Police inspects a room where there are no windows, no doors, no tables and is almost empty expect there is just a puddle of water. They found a dead man who obviously hung herself from the ceiling, but they are not able to figure out how this had happened.

John and Jacob entered the crime scene and easily able to solve the case.

How did the man die?

Can you place six matchsticks in a manner that each of the matchsticks is in touch with the other five matchsticks?

There is a box in which distinct numbered balls have been kept. You have to pick two balls randomly from the lot.

If someone is offering you a 2 to 1 odds that the numbers will be relatively prime, for example
If the balls you picked had the numbers 6 and 13, you lose $1.
If the balls you picked had the numbers 5 and 25, you win $2.

Will you accept that bet?

What's a single-digit number with no value?