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# what is the equation for this

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what is the formula for calculating the probability of rolling X Y-sided dice and getting a 1 on at least one of them?

Guest Nov 9, 2018
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$$P[\text{rolling at least one 1 on X Y sided dice}]=\\ 1 - P[\text{rolling zero 1's on X Y sided dice}]=\\ 1 - \left(\dfrac{Y-1}{Y}\right)^X$$

Rom  Nov 10, 2018