Originally Posted by

**ilovepsycho** Q. What is the chance that in 10 flips of a coin, no heads will come up? What is the conditional probability that, after 10 straight heads,

the 11th flip will be a tail (e.g, Prob(11th flip is a tail | 10 heads in a row)?

My answer to first question is 10C0 x 0.5^0 x 0.5^10 = 0.0009765625.

However, My stuck question is the 2nd, the conditional probability. How can I approch to the 2nd question? Please tell me how to answer to the 2nd.

p.s. Prob(11th flip is a tail | 10 heads in a row) = Prob(11th flip is a tail AND 10 heads in a row / Prob(10 heads in a row).

Prob(10 heads in a row) = 0.0009765725, as answered above. right? and then, what is Prob(11th flip is a tail AND 10 heads in a row?