Question

106) There are 2 Urns containing 5 red and 6
white balls and 3 red and 7 White balls
respectively. If two balls are drawn first Urn
without replacement and transferred to
second Um and then draw of another two
balls is made from it. What is the probability
that both the balls drawn are red? (€)
a) 52/77 b) 76/155 C) 65/726 d) 7/15
2) 62/7​

Answer 1

Step-by-step explanation:

Let A be the event of getting non-red ball in 1

st

draw

Let B be the event of getting non-red ball in 2

nd

draw

P(A)=

9

6

=

3

2

When a non-red ball is drawn in 1

st

draw, there are 5 non-red

balls and 3 red balls.

∴ from 5 non-red balls, one ball can be selected in

5

C

1

ways

∴P(B/A)=

8

5

Let C be event that atleast one ball is red.

P(C)=1− Probability of getting non-red ball

=1−P(A∩B)

=1−P(A).P(B/A)=1−

3

2

×

8

5

P(C)=

12

7