an unfair coin with pr[tails]= .15 is flipped 6 times. what is the probability of getting AT LEAST 1 tail in the 6 flips?

prob(tail) = .15

prob(heads) = .85

what we DON'T want is all 6 being heads
prob(6 heads) = (.85)^6

prob (at least 1 tail) = 1 - .85^6 = appr .623