A man lives on the fifteenth floor of an apartment building. Every morning he takes the elevator down to the lobby and leaves the building. In the evening, he gets into the elevator, and, if there is someone else in the elevator, or if it was raining that day, he goes back to his floor directly. Otherwise, he goes to the tenth floor and walks up five flights of stairs to his apartment. Can you explain why he does this?

What number does the below three word/phrase identify and why?
1. Deck
2. Year
3. Singing in the Rain

Find the missing number in the sequence below:

4 fathers, 2 grand-fathers and 4 sons went to watch the movie.What is the minimum number of tickets they need to buy ?

You have a 12 liters jug full of water. You have two empty 8 liters and 5 liters jug. How can you divide the water into two equal parts using these jugs?

My sock drawer has 26 blue socks, 13 pink socks, 33 green socks, and 12 red socks, how many socks would I have to pull out in the dark to be sure I had a matching pair?

It's a test that will check your IQ.

Suppose you have one 11 minute hourglass and one 13 minute hourglass.

Can you measure exactly fifteen minutes using them ?

This was asked in an interview with Coa-Cola.

The interviewer has given me 100 marbles(50 white and 50 black) and two empty boxes.
He then told me that he will leave the room and i need to place all the marbles in two boxes.

And When he come back, he will draw a marble from any of the two box and if the marble is white I will be hired.

Also
* No box can be empty.
* All 100 marbles must be placed in one of the two boxes.

So what should I have done?

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?

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?