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Complementary event

First, we determine the probability that none of the 3 throws are sixes.

P(no six) = 5·5·5 6·6·6 = 125 216

This means that 125 of the 216 different combinations that are possible when rolling a standard die three times do NOT contain one or more sixes. Therefore, there must be ( 216-125 ) = 91 combinations that contain at least one six.

Therefore, the probability of rolling at least one six in three throws is

P(at least one six) = 216 216 - 125 216 = 91 216 0.423 42.3%