posted by Stranger .
25 independent, fair coins are tossed in a row. What is the expected number of consecutive HH pairs?
If 6 coin tosses in a row give HHTHHH, the number of consecutive HH pairs is 3.
If you are going to answer other peoples questions you need to show them your work, just posting the final answer is no help. We try to show them how to get to the answer, and if we can we don't give the final answer, they learn better if they get to it themselves.