Question

A box contains 3 white and 2 red balls. A ball is drawn and another ball is drawn without replacing first ball, then the probability of second ball to be red is 

(A) 8/25

(B) 2/5 

(C) 3/5 

(D) 21/25

Answer 1

Answer is (B) 2/5

The second ball can be red in two different ways

(i) First is white and second red 

P(A) = 3/5 x 2/4 = 6/20

(ii) First is red and second is also red

P(B) = 2/5 x 1/4 = 2/20

Both are mutually exclusive events, hence, required probability is 6/20 + 2/20 = 8/20 = 2/5.