Question

Find the probability that a person flipping a coin gets​ (a) the sixth head on the eleventh ​flip, and​ (b) the first head on the third flip.

Answer 1

P(head) = 0.5

a) P(6th head on 11th flip) = P(five heads out of 10 flip) * P(flip)

                                          = 10C5 * 0.5⁵ * (1 - 0.5)^10-5 * 0.5

                                          = 0.1230

b) P(first head on third flip) = (1 - 0.5)² * 0.5 = 0.125