Answer:
P(X=n) = [n+9 C 9] (0.5)ⁿ⁺¹⁰
Explanation:
Number of times a head appears = 10
Total number of times the coin is flipped = X + 10
X = number of tails
Since it is certain that the last flip is a head , probability mass function of tail can be gotten out of (X + 10 -1) flips = X + 9 flips
P(X=n) = [n+9 C 9] (0.5)ⁿ⁺¹⁰