[ QUOTE ]
[ QUOTE ]
If one of the letters is an H it really doesn't effect the chance of an E showing up because if it wasn't an H it would still be something other than E.

[/ QUOTE ]
But it does affect it. If the first letter is an "h," then there are only 35 chances to get an "e." If it is not an "h," then there is 1/25 instead of 1/26 that it is an "e."

[/ QUOTE ]

Doing a binomial distribution calculation or taking an events liklihood to the power of trials takes this into account.

In this example the binomial distribtion of an event with the liklihood of an event that has the probability of occuring equal to 1/26 not occuring in 36 trials is 0.24366872185316. This is the same as (1/26)^36.

I am sorry I don't know how to explain it any better.