What number when divided in half becomes zero?

When you stop to look, you can always see me. But if you try to touch me, you can never feel me. Although you walk towards me, I remain the same distance from you. What am I?

Can you count the number of blocks in the picture below?

Rectify the following equality 101 - 102 = 1 by moving just one digit.

Prove that twice of ten is the same as twice of eleven.

Replace the question mark with the number below given a simple math problem.

A King wants to send the diamond ring to his girlfriend securely. He got multiple locks and their corresponding keys. His girlfriend does not have any keys to these locks and if he sends the key without a lock, the key can be copied in the way. How can King send the ring to his girlfriend securely?

The host of a game show, offers the guest a choice of three doors. Behind one is a expensive car, but behind the other two are goats.
After you have chosen one door, he reveals one of the other two doors behind which is a goat (he wouldn't reveal a car).

Now he gives you the chance to switch to the other unrevealed door or stay at your initial choice. You will then get what is behind that door.

You cannot hear the goats from behind the doors, or in any way know which door has the prize.

Should you stay, or switch, or doesn't it matter?

Can you find out who is the kidnapper in below Picture and why, Explain ?

Teacher ask the student

'Why are you standing on that chair in music class ?'.

what did student replied ?