You have 8 balls numbered 1, 3, 5, 7, 9, 11, 13 and 15. Select 3 balls and put them into the circles such that the sum of the numbers on them add up to 30.

Below is a little math equation, made of matchsticks, that does not add up. Can you move just one match stick and fix the equation?

You are to make one cut (or draw one line) – of course it needn’t be straight – that will divide the following shape into two identical parts.

Can you crack the unlock code for the lock using the 5 clues below?

• Clue #1: `682` – One number is correct and well placed
• Clue #2: `614` – One number is correct but wrongly placed
• Clue #3: `206` – Two numbers are correct but both are wrongly placed
• Clue #4: `738` – None of the numbers are correct
• Clue #5: `780` – One number is correct but wrongly placed

4 criminals are caught and are to be punished. The judge allows them to be freed if they can solve a puzzle. If they do not, they will be hung. They agreed.

The 4 criminals are lined up on some steps (shown in picture). They are all facing in the same direction. A wall separates the fourth man from the other three.

So to summarise :
Man 1 can see Man 2 and Man 3.
Man 2 can see Man 3.
Man 3 can see none of the others.
Man 4 can see none of the others.

The criminals are wearing hats. They are told that there are two white hats and two black hats. The men initially don’t know what colour hat they are wearing. They are told to shout out the colour of the hat that they are wearing as soon as they know for certain what colour it is.

They are not allowed to turn round or move. They are not allowed to talk to each other. They are not allowed to take their hats off.

Who is the first person to shout out and why?