John and Jacob are twin brothers. One of them is a liar whereas the other one is a truth-teller.

I called their home number and one of them picked up.
I asked. 'Does John lie?' The person replied with a yes.

Whom did I talk with, John or Jacob?

What mathematical symbol can be put between 5 and 9, to get a number bigger than 5 and smaller than 9?

What can run but never walk, have a mouth that never speaks, have a head that never weeps, and have a bed but never sleeps?

What is black when you buy it, red when you use it, and gray when you throw it away?

A newspaper is supposed to have 60 pages, but pages 24 and 41 are missing.
Which other pages won't be there?

Chocolate costs 6 rupees and a Toy costs 5 rupees. If you have 32 rupees in total, how many chocolates and how many Toys can be purchased with that amount?

Why is it against the law for a man living in Delhi to be buried in Mumbai?

Can you spot the hidden girl in the picture below?

The captain of a ship is telling you an interesting story and then poses a question. He says, “I have travelled the oceans far and wide. One time, two of my sailors were standing on opposite sides of the ship. One was looking west and the other one east. And at the same time, they could see each other clearly. Can you tell me how that was possible?”

I want to fill my bucket using both cold and hot water.
I have two taps for both cold and hot water. The hot water tap fills the bucket in exact 6 hours and the cold water tap fills the bucket in exact 4 hours.
I turn both of them simultaneously but I forgot to turn off another tap which removes the water out of the bucket. This tap can empty the bucket in 12 hours.

How Long will it take to fill the bucket?