Question

Let the random variable x represent the number of times a fair coin needs to be tossed till two consecutive heads appear for the first time. The expectation of x is

Answer 1

The expectation of x is 4.

Step-by-step explanation:

According to question, it is given that the random variable x is the no. of times a fair coin is tossed till two consecutive heads appear for the first time.

Now, see the total outcomes.

                        = T T

                         = T H

                        = H T

                        = H H

there are total four outcomes and it shows that for the worst condition two heads come simultaneously at last. Which means the x variable is 4.