A box contains 6 red, 4 blue, 2 green and 4 yellow hats. Two hats are picked at random, what is the probability that one is blue and one is yellow?

Explanation

Total number of hats = 6 + 4 + 2 + 4 = 16 Let S be the sample space. Then, n(S) = number of ways of drawing 2 hats out of 16 = ¹⁶C_2 = (16 × 15 )/( 2 × 1) = 120 Let E= event of drawing two hats so that one is blue and one is yellow. n(E) = ⁴C_1×⁴C_1= 4 × 4= 16 ∴ P (E) = (n(E))/(n(S)) = 16/120 = 2/15 IBPS RRB Scale I 2021 Prelims Memory Based Paper