Your question is Sequence Distribution and Moments. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
A fair coin is tossed repeatedly until a specific sequence appears. How would you identify the underlying probability distribution, and what are its expectation and variance?
Because the target sequence is unspecified, describe a general method that accounts for overlapping partial matches. Demonstrate the method using the illustrative sequence HTH, including its probability distribution representation, expectation, and variance.