# Math

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Seven standard, six-sided dice are rolled, one after the other. What is the probability that:

a) exactly one of them shows a six?
c) there is at least one that shows a six?

• Math -

prob(6) = 1/6
prob(not6) = 5/6

a) exactly 1 out of 7 tries to be 6
= C(7,1) * (1/6)^1 * (5/6)^6
= .3907 rounded to 4 decimals

b) at least one 6 ---> 1 - prob(all not6)
= 1 - C(7,7) * (1/6)^0 * (5/6)^7
= 1 - .2791
= .7209

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