A bag contains 8 red and 5 white balls. 2 balls are drawn

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A bag contains 8 red and 5 white balls. 2 balls are drawn at random. What is the probability that both are white ?

1. 5/16
2. 2/13
3. 3/26
4. 5/39

Correct Option: D

n(S) = Number of ways of drawing 2 balls out of 13 = ¹³C₂ = 13 x 12 / 2= 78
n(E) = No. of ways of drawing 2 balls out of 5 = ⁵C₂ = 5 x 4 / 2 = 10

∴ P(E) = n(E)/n(S) = 10/78 = 5/39