three unbiased coins are tossed . what is the probability of getting at most 2 heads ?
"here s = { ttt , tth , tht , htt , thh , hth , hht , hhh } let e = event of getting at least two heads = { ttt , tth , tht , htt , thh , hth , hht } p ( e ) = n ( e ) / n ( s ) = 7 / 8 . answer a ."
negate_prob(divide(const_1, power(const_2, const_3)))