Question

A box B₁ contains 1 white ball and 3 red balls. Another box B₂ contains 2 white balls and 3 red balls. If one ball is drawn at random from each of the boxes B₁ and B₂, then find the probability that the two balls drawn are of the same colour.

Answer 1

Box B1	1 White Balls 3 Red Balls

 

Box B2

2 White Balls 3 Red Balls

∴ P(Required) = P(Both are white) + P(Both are red)

= `1/4 xx 2/5 + 3/4 xx 3/5`

= `20/20 + 9/20`

= `11/20`