1
$\begingroup$

A fair coin is tossed $10$ times, the tosses being indipendent of each other. I have to find the probability that 3rd, 4th and 5th tosses are identical.

I have no idea how to calculate. please help.

1 Answers 1

2

Hint: Two possibilities (i) three heads and (ii) three tails. What is the probability of $3$ consecutive heads? Of three consecutive tails? Add.

The fact that there were $10$ tosses is irrelevant. And the fact that $3$, $4$, and $5$ are next to each other s irrelevant. We would have the same answer to "what is the probability the the $2$nd, $5$th, and $10$th tosses are identical?"

  • 0
    I understand, thanks a lot..2012-10-04