Tuesday 13 October 2009

A Climbing Snail

I have a new brain teaser:


There's a snail which is at the bottom of a well. It wants to get out of the well.
The well is 30m tall. The snail can only climb in the morning. In the evening, the snail slips down.
Every time the snail climbs, the snail climbs for 3 m. Every time the snail slips down, it slips for 2m.

How long will it take the snail to get out of the well?

1 comments:

michael said...

30 days