Statistics And Probability Question 260

Question: A bag contains 3 red, 4 white and 5 black balls. Three balls are drawn at random. The probability of being their different colours is

[RPET 1999]

Options:

A) $ \frac{3}{11} $

B) $ \frac{2}{11} $

C) $ \frac{8}{11} $

D) None of these

Show Answer

Answer:

Correct Answer: A

Solution:

  •         Probability  $ =\frac{^{3}C_1{{.}^{4}}C_1{{.}^{5}}C_1}{^{12}C_3} $  $ =\frac{3}{11} $ .