A bag contains 6 white and 4 black balls 2 balls are drawn at random Find the probability that they ...........

Quantitative Aptitude ( CCS) Probability

A bag contains 6 white and 4 black balls .2 balls are drawn at random. Find the probability that they are of same colour.

1/2

7/15

8/15

1/9

Let S be the sample space

Then n(S) = no of ways of drawing 2 balls out of (6+4) =10C2

10 =10*92*1 =45

Let E = event of getting both balls of same colour

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

=6C2+4C2

=6*5/2*1+4*3/2*1 =15+6 = 21

Therefore, P(E) = n(E)/n(S) = 21/45 = 7/15

Hence, option 2 is the correct answer.

Submit Error