bias p

000 (1-p)^3
001 (1-p)^2 * p
010 (1-p)^2 * p
011 (1-p) * p^2
100 (1-p)^2 * p
101 (1-p) * p^2
110 (1-p) * p^2
111 p^3

sum them all = 1
(1-p)^3 + 3 * (1-p)^2 * p + 3 * (1-p) * p^2 + p^3

Or3(a,b,c) = a or b or c 	1-(1-p)^3 max when p = 1, result 1
OneInThree(a,b,c)               3 * (1-p)^2 * p max when p = 1/3, result 4/9