If we flip 6 coins, what is the probability of getting at least 2 heads?

There are 2^6=64 possible outcomes. The probability of getting at most one HEAD is 7/64 so the answer is 1 - 7/64 = 57/64.

The probability  = 1 − P( 0 heads)  − P(1 head)

P(0 heads)  =  (1/2)^6  =  1/64

P (1 head)  = C(6,1) (1/2)(1/2)^5 = 6 *(1/2)^6  =  6/64

So....the total probability  = 1 − 1/64 − 6/64  = 57/64