# Equality in binary choices

1. Feb 12, 2014

### jk22

Suppose we have 2n binary choices. Then the probability of having the same number of results is :

C(2n,n)/2^(2n) ?

I don't know if this is true, since for the case n=1million, we have a probability as high as 1/2000, which seems quite important ?

2. Feb 12, 2014