What brings you down but never up?

I am lying and I always lie. Tell me whether I am lying or telling the truth.

The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

What's a single-digit number with no value?

An express train takes 3 seconds to enter the tunnel which is 1 km long.
If it is travelling at 120 km an hour, how long will it take to pass completely through the tunnel?

What is the difference between a jeweller and a jailer?

See the given image carefully. What you have to do is move the blue checkers in the position of the black checkers and vice versa. You are only allowed to move the checker to an adjacent empty space. Do it in the least possible moves.

Find the hidden panda in the image below.

Can you find the six hidden animals in the picture below?

If you were to put a coin into an empty bottle and then insert a cork into the neck, how could you remove the coin without taking out the cork or breaking the bottle?