Question

8. A bag contains 8 red and 5 white balls. Three balls are drawn at random. Find the
probability that:
(i) All the three balls are white.
(ii) All the three balls are red.
(iii) One ball is red and two balls are white.
[NCERT EXEMPLAR)

Answer 1

Answer:

i) 5/13

ii) 8/13

iii)  40/143

Step-by-step explanation:

Total balls = 13

red balls =8

white balls = 5

i )   for all white balls

          no. of white balls / total no. of balls

         =  5/13

ii) for all red balls

         no. of red balls/ total no. of balls

          = 8/13

iii) total outcomes = ¹³C₃

   for 2 white balls =  ⁸C₂

    for 1 red ball =  ⁵C₁

P(1 red ball and 2 white balls)  = ⁸C₂ x ⁵C₁ / ¹³C₃

                                               After solving combinations

                                                =  40/143

*_*