In: Statistics and Probability
A coin has a probability of 1/4 for head, and is repeatedly
tossed until
we throw head. The successive results of the toss are independent
of each other.
What is the probability that the first time we throw head after an
odd number of toss?
Hint: Use the law of total probability and consider the event that
the
first toss is head is, and her complement, as conditioning
events.
Correct answer: 3/7