Given: A bag contains 8 red and 5 white balls.
By using the formula,
P (E) = favourable outcomes / total possible outcomes
Total number of ways of drawing three balls at random is 13C3
n (S) = 286
(i) Let E be the event of getting all white balls
E= {(W) (W) (W)}
n (E)= 5C3=10
P (E) = n (E) / n (S)
= 10 / 286
= 5/143
(ii) Let E be the event of getting all red balls
E = {(R) (R) (R)}
n (E)= 8C3 =56
P (E) = n (E) / n (S)
= 56 / 286
= 28/143
(iii) Let E be the event of getting one red and two white balls
E = {(R…. 80th R)}
n (E)= 8C15C2 = 80
P (E) = n (E) / n (S)
= 80 / 286
= 40/143
