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

A word I know has six letters it contains, remove one letter and 12 remain. What is it?

We have shown you a regular water barrel as below. Without using any measuring device can you check if the barrel is more than half-filled or less than half-filled?

Can you count the number of quadrilaterals in the picture below?

In the city of Brain Teasers, 5% of people do not list their phone numbers. Now if we select random 100 people from the phone directory, then how many people selected will have unlisted phone numbers?

What begins with T, ends with T, and has T in it?

Why do you find that most of the buildings are deprived of the 13th floor?

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

A person was found dead on a big green land with no trees or buildings around. When the police arrived, they found a piece of rock lying next to him and the man was wearing clothes comprising of red, blue and yellow colours.

Can you tell who the person is and what was the cause of death?

Two fathers and two sons went fishing one day. They were there the whole day and only caught 3 fish. One father said, that is enough for all of us, we will have one each. How can this be possible?