Question

Suppose an urn has six balls, three red, two blue, and one yellow. On any draw from the urn, all balls in the urn are equally likely to be drawn. Suppose that two balls are drawn, in sequence without replacement, that is, the second ball is drawn without replacing the first ball in the urn. What is the probability that the second ball drawn is blue

Answer 1

1 / 3

Explanation:

Number of balls :

Red, R = 3 ; Blue, B = 2 ; Yellow, Y = 1

Total = 6

From two draws without replacement, probability that 2nd draw is blue :

Possibilities :

P(RB) or P(YB) or P(BB)

P(RB) = 3/6 * 2/5 = 6/30

P(YB) = 1/6 * 2/5 = 2 /30

P(BB) = 2/6 * 1/5 = 2 / 30

HENCE,

P(RB) + P(YB) + P(BB)

6/30 + 2/30 + 2/30 = 10/30 = 1/3