A coin is tossed until a head appears or it has been tossed 3 times. Given that head doesn't appear on the first toss, the probability that coin is tossed 3 times is

A coin is tossed until a head appears or until it has been tossed three times. Given that 'head' does not occur on the first toss, what is the probability that the coin is tossed thrice?

A coin is tossed again and again. If tail appears on first three tosses, then the chance that head appears on fourth toss is

A biased coin is tossed repeatedly until a tail appears for the first time. The head is 3 times likely to appear as the tail. The probability that the number of tosses required will be more than 4, given that in first two toss no tail has occur, is

A coin is tossed until a head appears. What is the expectation of the number of tosses required ?

A coin is tossed until a head appears. What is the expectation of the number of tosses required ?

A coin is tossed three times. Given that at least one head appears, what is the probability that exactly two heads will appear?

A coin is tossed until a head appears or the tail appears 4 times in succession. Find the probability distribution of the number of tosses.