View Full Version : Math problem

Tyler Durden
08-30-2005, 10:56 PM
It's a probability question:

If you flip eight coins, what are the odds that exactly four land heads and exactly four land tails?

I got 1/256 but I'm not too bright so it's probably wrong.

Thanks in advance.

08-30-2005, 11:00 PM
There are eight coins, choose four to be heads: 8! / 4! * 4! = 70, so 70 / 256 is the probability that four come heads and four come tails.

08-30-2005, 11:00 PM
There is a probability forum. Anyways it's 1/256 for precisely HHHHTTTT. Also for HHHTTTTH. There are C(8,4) = 70 combinations of this, so it's 70/256

Matt Flynn
08-30-2005, 11:04 PM
i get 70/256, but i cannot add.