Question

An urn contains 9 balls two of whigh are red, three blue and four black. Three balls are drawn at random. The probability that they are of same colour is​

Answer 1

Answer:

5/84

Step-by-step explanation:

Probability of choosing 3 red = 0

Probability of choosing 3 blue= C(3,3) = 1

Probability of choosing 3 black= C(4,3) = 4

Probability of choosing any 3 from 9 balls = C(9,3) = 84

P (same colour) = ( 0+C(3,3)+C(4,3) ) ÷ C(9/3) = 5/84