Got Any Puzzles?

[mike_w]

As per the title really - anybody got any decent puzzles they might want to share? I'm thinking more along mathematical lines here - things like Monty Hall, Hilbert's Hotel, 1=2 proof, how a melting ice cube affects the water level, or this:

A 40 kg rock was used to weigh things on a balance scale. The rock was dropped and it broke into four pieces. Using combinations of the four rocks all the whole number weights from 1 to 40 kg could be weighed on the balance scale. What are the four weights?

[Source]

Thanks

Mike.

[awm]

Don't get it. Using the solution on the page how do you get 2, a whole number weight (ahhhh, terrible phrasing).

[Gerrard]

Don't get it. Using the solution on the page how do you get 2, a whole number weight (ahhhh, terrible phrasing).

You put the 1Kg piece on the same side of the item you are weighing and then put the 3Kg piece on the other side. For the scales to be balanced, the item needs to be 2Kg.