Suppose that a fair coin is tossed repeatedly until
Chapter 4, Problem 11(choose chapter or problem)
Suppose that a fair coin is tossed repeatedly until exactly k heads have been obtained. Determine the expected number of tosses that will be required. Hint: Represent the total number of tosses X in the form X = X1 + ... + Xk, where Xi is the number of tosses required to obtain the ith head after i 1 heads have been obtained.
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