If you toss a coin often enough the probability is 1.
The probability of 9 H in the first 9 tosses is (1/2)9 = 1/512
Chat with our AI personalities
It is (1/2)9 = 1/512
The number of trials: n = 9, the number of success: r = 4. The probability of success: P(H) = 1/2, the probability of failure: P(T) = 1/2. P(exactly 4 heads in 9 tosses) = 9C4 x (1/2)^5 x (1/2)^4 = 126(1/2)^9 = 0.246 P(at most 2 heads) = P(none heads) + P( 1 head) + P(2 heads) = 9C0[(1/2)^9][(1/2)^0] + 9C1[(1/2)^8][(1/2)^1] + 9C2[(1/2)^7][(1/2)^2] = 1(1/2)^9 + 9(1/2)^9 + 36(1/2)^9 = (1 + 9 + 36)(1/2)^9 = 46(1/2)^9 = 0.09
well, it will have 6 times of the greater chance.
2/9
No heads means that every toss lands tails. (0.5)30= 9.3 x 10-10 Note that 109 = 1 trillion, so the probability can be stated this event is likely to occur about 9 times in 10 trillion tosses.