If you go to the movies and you're paying, is it cheaper to take one friend to the movies twice, or two friends to the movies at the same time?

Which three-digit number, made of consecutive digits, like 567, is 2 less than a cube and 2 more than a square?

There are 20 people in an empty, square room. Each person has full sight of the entire room and everyone in it without turning his head or body, or moving in any way (other than the eyes). Where can you place an apple so that all but one person can see it?

There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

Which is the smallest number that you can write using all the vowels exactly once?

There are forty elephants and they have forty-fore heads. How can this be possible?

If six children and two dogs were under an umbrella, how come none of them got wet?

Make eight squares by moving only two matchsticks.
Note- Square can be of different sizes.

A beggar on the street can make one cigarette out of every 6 cigarette butts he finds. After one whole day of searching and checking public ashtrays the beggar finds a total of 72 cigarette butts. How many cigarettes can he make and smoke from the butts he found?

Your last good ping-pong ball fell into a narrow metal pipe embedded one foot deep in concrete.
How can you get it out undamaged, if all the tools you have are your tennis paddle, shoe laces, and plastic water bottle, which does not fit into the pipe?