The Elephant Strikes Back
Here is a nice logic riddle. I asked it one of my friends a few weeks ago, and because he didn’t solve it immediately I thought it would be nice to ask it here. It deals with an Elephant.
The Elephant is standing on a raphsody (or even a simple boat, suit yourself) in the middle of a lake. Suddenly, it jumps into the water. My humble question: what happens to the water level in the lake? Would it become higher, lower, or remain the same?
Write down your answer in the comment sections. It is much easier then you expect - don’t overthink it.
September 4th, 2006 at 9:56
Archimides would tell you that, wherever he was, the elephant displaces an amount of water equal to its weight, regardless of whether he’s on the boat or in the river.
He’s wrong.
The splash could get water flying out of the lake which will reduce the level of water, depending on the lake’s size.
– Arik
September 4th, 2006 at 19:08
I think he’s right. If the elephant didn’t splash water out of the lake, the level would remain the same as dictated by displacement laws.
March 22nd, 2007 at 9:13
[…] Over six months ago, I presented you this small riddle, about the elephant on the lake. I was surprised to find that it still bothers some of my friends; last night, it seems, Lior wasted precious sleeping hours trying to proove a mathematical solution. So for all who are still interested, here is my solution and proof; do try to solve it yourself before looking at the answer. I included a bit of simple math in there, and I apologize for being so unpolite; but it is the easiest way to convince some people that this is really the solution. […]