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

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?

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

If "P" means "-", "Q" means "/", "R" means "+", and "S" means "*" then find the value of the following:

21 Q 7 R 9 S 10 P 13

It belongs to you, but other people use it more than you do. What is it?

John’s parents have three sons: Snap, Crackle, and what’s the name of the third son?

The following alphametic has only one solution. Can you find it?
ENLIST + SILENT + LISTEN = ANAGRAM

PS: You may start the number from 0.

In a chess board, the queen piece can move horizontally, vertically and diagonally freely. The picture represents the same.Can you place 8 queens on the board in a manner that none of the queens can attack each other?

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

If it took eight men ten hours to build a wall, how long would it take four men to build it?