Professor Layton Wiki
Professor Layton Wiki
Security Guard Test Iron Balls Three Children

Iron Balls is a puzzle in the UK version of Professor Layton and the Curious Village.


Here are 12 iron balls on the kind used in school science experiments. They are all the same size and shape. 11 of them weigh 200g while just one weighs 100g.

What is the least number of times you can use the scale shown to find out which of the iron balls is the 100g one?

Click a Tab to reveal the Hint.

Your task is to find which of the 12 iron balls weighs 100g.

Since the others weigh 200g, you are trying to find out what weighs half of that.

How can you find something that looks the same but has half weight?



That's right!

You don't need to use the scale at all! If one of the iron balls is half the weight of the others, you can tell the difference just by holding them!


A big thanks to