A fair coin is tossed n - times such that the probability of getting at least one head is at least 0 . 9 . Then the minimum value of n is _______.

Step-by-step solution

When a coin is tossed, then probability of head, P Head = P Tail = 1 2 Therefore, 1 - P (All tail) ≥ 0 . 9 ⇒ 1 - 1 2 n ≥ 0 . 9 ⇒ 1 2 n ≤ 1 10 ⇒ n min = 4 .