Religion and Ethics Forum

General Category => Literature, Music, Art & Entertainment => Topic started by: jeremyp on August 01, 2016, 01:38:55 PM

Title: A puzzle for your entertainment
Post by: jeremyp on August 01, 2016, 01:38:55 PM
I have 100kg of potatoes. Each potato is 99% water. I dehydrate the potatoes to the point where they are only 98% water, how much do they weigh?

Title: Re: A puzzle for your entertainment
Post by: SqueakyVoice on August 01, 2016, 08:09:28 PM
50kg.

If 100kg is 99% water then 1kg is the dry (/non-water) mass.

The dry mass doesn't change, so the water must now be the remaining 98%. Working that back shows that if 2% is 1kg, then 98% must be 49kg. Giving a total mass of 50kg.
Title: Re: A puzzle for your entertainment
Post by: jeremyp on August 01, 2016, 08:13:00 PM
50kg.

If 100kg is 99% water then 1kg is the dry (/non-water) mass.

The dry mass doesn't change, so the water must now be the remaining 98%. Working that back shows that if 2% is 1kg, then 98% must be 49kg. Giving a total mass of 50kg.

Well done. This is the potato paradox.

https://en.wikipedia.org/wiki/Potato_paradox

I'd never heard of it before today but I found it quite intriguing.
Title: Re: A puzzle for your entertainment
Post by: Hope on August 01, 2016, 08:47:04 PM
Paradox though it might be, it highlights just how much water can weigh!!
Title: Re: A puzzle for your entertainment
Post by: jeremyp on August 01, 2016, 09:24:14 PM
Paradox though it might be, it highlights just how much water can weigh!!

Technically, it isn't a paradox, it's merely counter-intuitive.
Title: Re: A puzzle for your entertainment
Post by: SqueakyVoice on August 01, 2016, 09:59:34 PM
Technically, it isn't a paradox, it's merely counter-intuitive.
The Counter-Intuitive POTATO!

(A distant cousin of the Curious Orange. ..)