Question

In a bag 13 balls are white and 7 are blue..find the probability in which both of same colour

Answer 1

Thanks for asking the question!

ANSWER::

Number of ways of selecting two balls from 13 + 7 = 20 balls is ²⁰C₂ = (20x19)/2 = 190

Number of ways of selecting two white balls from 13 white balls = ¹³C₂ = (13x12)/2 = 78

Number of ways of selecting two blue balls from 7 blue balls = ⁷C₂= (7x6)/2 = 21

Favorable ways = 78 + 21 = 99

Required probability = Favorable ways / Total ways = 99/190

Hope it helps!