First slide

Theorems of probability

Question

A bag contains 3 red and 3 green balls and a person draws out 3 at random. He then drops 3 blue balls into the bag and again draws out 3 at random. The chance that the 3 later balls being all of different colors is

Moderate

A

15%
B

20%
C

27%
D

40%

Solution

The required probability is
$\frac{^{3} {C_{1}}^{3} C_{2}}{^{6} C_{3}} \frac{^{2} {C_{1}}^{1} {C_{1}}^{3} C_{1}}{^{6} C_{3}} + \frac{^{3} {C_{2}}^{3} C_{1}}{^{6} C_{3}} \frac{^{1} {C_{1}}^{2} {C_{1}}^{3} C_{1}}{^{6} C_{3}}$
$\begin{array}{l} = 2 \frac{9}{20} \times \frac{6}{20} \\ = \frac{27}{100} \end{array}$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App