The Daily Static
  The Daily Static
UF Archives
Register
UF Membership
Ad Free Site
Postcards
Community

Geekfinder
UFie Gear
Advertise on UF

Forum Rules
& FAQ


Username

Password


Create a New Account

 
 

Back to UserFriendly Strip Comments Index

Attn dennismv, coins by DesiredUsername 2012-01-08 01:48:43
I posted a numeric answer yesterday.

I think I just worked it out analytically.

I get the same answer as you said for the average number of flips starting from zero. Call that x. In the case of two heads, x=6.

If you flip the first coin and get heads, then you have two options for the next flip. Either heads (and your number of flips is two) or tails. If you get tails, you go back to the starting point and you have six flips expected. However, you only need to do that half the time.

The expected number of flips will be = 0.5*(1) + 0.5*(x+1), or 4 flips more.

This can easily be extended to N heads in a row, starting with one head. I'm still working on the final analytic solution, but I'm getting tired..
[ Reply ]
  Ok, here is my guess by DesiredUsername2012-01-08 02:15:37
    Plugging in a few numbers by hand by DesiredUsername2012-01-08 02:38:09

 

[Todays Cartoon Discussion] [News Index]

Come get yer ARS (Account Registration System) Source Code here!
All images, characters, content and text are copyrighted and trademarks of J.D. Frazer except where other ownership applies. Don't do bad things, we have lawyers.
UserFriendly.Org and its operators are not liable for comments or content posted by its visitors, and will cheerfully assist the lawful authorities in hunting down script-kiddies, spammers and other net scum. And if you're really bad, we'll call your mom. (We're not kidding, we've done it before.)