A bag contains 6

given: bag which contains 6 red, 8 blue and 4 white balls

formula:

two balls are drawn at random, therefore

total possible outcomes are ¹⁸C₃

therefore n(S)=816

(i) let E be the event of getting one red and two white balls

E= {(W) (W) (R)}

n(E)= ⁶C₁⁴C₂=36

(ii) let E be the event of getting two blue and one red

E= {(B) (B) (R)}

n(E)= ⁸C₂⁶C₁=168

(iii) let E be the event that one of the balls must be red

E= {(R) (B) (B)} or {(R) (W) (W)} or {(R) (B) (W)}

n(E)= ⁶C₁⁴C₁⁸C₁+⁶C₁⁴C₂+⁶C₁⁸C₂=396