Question

The sample space of the experiment: 'A coin is tossed until two consecutive tails appeared and the total number of coin tosses are recorded' is

• A. positive integers
• B. natural numbers
• C. natural numbers $\ge 2$

Answer 1

The correct option is C natural numbers $\ge 2$

Look, I toss a coin. Either it will show a head or a tail. If it shows a head I will have to toss it again to see one of my two tails. And then at least once more to see another tail. If in the first throw itself it shows a tail, again I have to throw it once more at least to see the second tail. So in any case the coin has to be tossed at least 2 times. And then it can go on till we get two consecutive tails. So set of natural numbers greater than or equal to 2 will be the correct answer.