How can you write nineteen in a manner that if we take out one, it becomes twenty?

What can you hold in your right hand, but never in your left hand?

Which number should replace the question mark?

John speaks the truth only once a day in a week. Below are a few hints for you:

First: Days are Sunday, Monday and so on.
Second: One day he says, "I lie on Monday and Tuesday".
Third: On the next day, he says, "Today is either Thursday, Saturday or Sunday".
Fourth: On the next day, he says, "I lie on Wednesday and Friday".

Can you identify the day on which he speaks the truth?

A man has to get a fox, a chicken, and a sack of corn across a river.

He has a rowboat, and it can only carry him and one other thing.
If the fox and the chicken are left together, the fox will eat the chicken.
If the chicken and the corn are left together, the chicken will eat the corn.

How does the man do it?

James bond was pushed out of an aeroplane without any parachute.
He survived, How come?

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?

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?

I am looking for a word that change both gender and number when i add the letter 'S'.

What Word am I Looking For ?

Suppose we lay down two cups in front of you. One of the cups is filled with tea and the other one with coffee. Now we ask you to take a spoonful of tea and mix it with the coffee. At this moment, the coffee cup has a mixture of tea and coffee. You have to take that mixture (spoonful) and add it back to the tea.

Can you now tell if the cup of coffee has more tea or the cup of tea has more coffee?