You play a coin flipping game with 5 coins. On round 1 you flip all of them. On round 2, you pick up all the ones that came up tails (leaving all the heads alone) and flip them again. You continue to do this until all the coins are heads. For example:

Round 1:  H T T H T
Round 2:  - H T - H
Round 3:  - - T - -
Round 4:  - - T - -
Round 5:  - - H - -

Done in 5 Rounds.

What is the expected number of rounds you'll need to finish the game?
What is the probability you will finish the game in 3 rounds or less?

(In reply to No Subject by Michael Cottle)

Well my first post to this site was a bunch of complete jibberish. :( My apologies. Anyway, recursions of this type are easily setup in Excel. Much more easily than trying to post comments over varying computer formats. However, it did look fine on my screen before I sent it.

Posted by Michael on 2004-11-21 17:00:50