What does this rebus means ?

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

What is the four-digit number in which the first digit is one-third the second, the third is the sum of the first two, and the last is three times the second?

Which number should replace the question mark?

A bomb exploded in a room full of married couples and no one died. How?

In the image below, you can see two glasses and two matchsticks.You need to move four matchsticks in such a manner that the crosses come inside the glasses. Note: you cannot move the crossed.

A man was gazing through the window of the 23rd floor of the building. He suddenly opened the window and jumped on the other side of the window. On landing on the floor, there was not a sheer mark of injury on him.

How can that be possible if he did not use any kind of parachute and did not land on a soft surface?

Consider this: Arnold Schwarzenegger has a big one. Michael J. Fox has a small one. Prince doesn’t have one. The Pope has one but never uses it. Bill Clinton has one and uses it all the time. What is it?

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

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