If you roll a 10 sided die 3 times how to calculate the odds of it landing on 10 exactly twice?0 times: 90% chance to not land -> .9^31 times: 1-.9^3 - (odds of it landing 2 or 3 times)2 times: This is what I want to know how to calculate3 times: .1^3
>>1556173the chance of 10 multiplied by the chance of 10 multiplied by the chance of not-10 gives you the chance of each individual arrangement of 2 successes and 1 failure, in this case, SSFyou then need to multiply this by the number of possible arrangements of 2 successes and 1 failure, which is threeSSFSFSFSSthus 3 x 0.1 x 0.1 x 0.9 = 0.027also, you're wrong about the chance of 1 ten. your formula gives 0.271, but the correct formula (same as above) gives 0.243. yours is the chance of AT LEAST ONE 10.the full formula is herehttps://en.wikipedia.org/wiki/Negative_binomial_distribution#Probability_mass_function
