Which tank will fill first?

You are confined in a room and given two metal rods. Out of these two rods, one is magnet and the other is the iron rod. They look starkly similar. You don't have any other metal object in the room.

How will you decide which one of those is magnet?

You’re out on the water and see a boat filled with people. You look away for a second and look back again, but this time you don’t see a single person on the boat. Why? Hint: The boat did not sink.

If you toss a coin 10 times and it lands heads up every time, what are the chances it will land heads up if you toss it again?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

Andrew’s doctor gives him three pills and tells him to take one every half hour. How much time will have passed by the time Andrew’s taken all three pills?

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?

A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?

There’s a one-story house in which everything is yellow. Yellow walls, yellow doors, yellow furniture. What colour are the stairs?

How high do you have to count before you use the letter “a” in the English spelling of the whole number?