Question

An urn contains 7 pink and 8 black balls. Five balls are randomly drawn from the urn in succession, with replacement. What is the probability that all five balls drawn from the urn are black?

Answer 1

prob = C(8,5)/C(15,5) = 56/3003 = 8/429

or

prob = (8/15)(7/14)(6/13)(5/12)(4/11)
= 8/429