Which is heavier: a ton of bricks or a ton of feathers?

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

John is looking at Jenifer, but Jenifer is looking at Jacob. John is married, but Jacob is not.

Is a married person looking at an unmarried person ?

Which number should replace the question mark?

A woman lives in a skyscraper thirty-six floors high and is served by several elevators which stop at each floor going up and down. Each morning she leaves her apartment and goes to one of the elevators. Whichever one she takes is three times more likely to be going up than down. Why?

I am under you when I am whole.
I shift above you if you remove the first letter.
I come all around you if you remove the second as well.

Can you tell me who I am?

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 are presented with three boxes. One of them has a red ball inside and the other two have a black ball inside each of them. You are asked to pick up the one with red ball and you pick one. Now, one of the other boxes is opened and it is found to have a black ball.

You are presented with a chance to change your box with the one that is left closed. Will you change your box? Why or why not?

What has no start, end, or centre?

The current time can be represented by below textual rebus.

0
=========
B.Sc
LLB

Can you tell us the current time?