P(9) = 1/15, P(1 to 8) = 8/15 with replacement
From the problem statement we can have anything from one 9 to seven 9's
P(9 greatest)= ∑i = 1, 7[C(7, i)*(1/15)^i *(8/15)^(7-i)]
From the problem statement we can have anything from one 9 to seven 9's
P(9 greatest)= ∑i = 1, 7[C(7, i)*(1/15)^i *(8/15)^(7-i)]
where C(7, i) = 7!/[(7 - i)!(i!)] and ∑i = 1, 7 sums from i = 1 to i = 7
Now you can solve to get the final answer.
