Question

6. A box contains 6 red balls and 4 black balls. If one ball is drawn at random
and replaced after each draw, find out the probability of drawing 3 red balls in
successive draws​

Answer 1

Step-by-step explanation:

Let S be the sample space

Then n(S)= number of ways of drawing 2 balls out of (6+4)=10

⇒

10

C

2

=

2×1

10×9

=45

Let E= event of getting both balls of same color

Then,n(E)= no of ways (2 balls out of six) or (2 balls out of 4)

=

6

C

2

+

4

C

2

=

2×1

6×5

+

2×1

4×3

=15+6=21

∴P(E)=

n(S)

n(E)

=

45

21

=

15

7