Question

An urn contains 5 red cubes, and 4 blue cubes. If we draw 3 cubes what is the probability we draw exactly 2 red cubes?

Answer 1

we have given

red = 5

blue = 4

total = 9

we want draw 3 cubes

probability that we draw exactly two red cubes

$=\frac{\binom{5}{2}\binom{4}{1}}{\binom{9}{3}}$

= 0.4761

probability we draw exactly 2 red cubes is 0.4761