Six glasses are in a row. The first three are filled with milk and the last three are empty. By moving only one glass, can you arrange them so that the full and the empty glasses alternate?

Different lights make me strange by changing me into different sizes. What am I?

The host of a game show offers the guest a choice of three doors. Behind one is an 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?

I know a 5-digit number having a property that With a 1 after it, it is three times as large as it would be with a one before it.

Guess the number?

What is black when you buy it, red when you use it, and gray when you throw it away?

Why Aeroplane windows are round?

Which digit occurred maximum times between the number 1 and 1000?

The day before yesterday I was 25 and the next year I will be 28. This is true only one day in a year. What day is my birthday?

I’m tall when I’m young, and I’m short when I’m old. What am I?

Below is the sum of symbols in each row and column in the figure. Analyzing the figure, can you find out the value of the symbols?