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

Six glasses are in a row. The first three are filled with milk and the last three are empty. By moving only one glass, can you arrange them so that the full and the empty glasses alternate?

In the given figure, move three matchsticks so that the resulting figure contains two rectangles.

I am the fastest animal but cannot climb the tree. What am I?

You can hear me, but you can't touch or see me.

What am I?

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

A patient was diagnosed with some ailment. He was given five different tablets to take at night at an interval of 15 minutes.

How long will it take the patient to consume all the five tablets?

Outside a tattoo artist's shop, there was a signboard which read 'I make tattoos on only them who do not tattoo themselves'.

Reading it what do you think, does the tattoo artist tattoo himself?

Find The Next Number in this series.
1, 2, 6, 42, 1806 ?

Can you find out the next digit in the following series ?

0, 0, 1, 3, 2, 6, 3, 9, 4, 12, 5, ?