Question

From a bag containing 6 white balls, 3 black balls and 13 red balls, two balls are drawn at random. What is the probability that they are both red without replacement?

a) 26/77
b) 9/10
c) 1/2
d)5/77

Answer 1

Probability [Both ball red without replacement] = 26 / 77

Explanation:

Given:

Number of white ball in beg = 6 balls

Number of black ball in beg = 3 balls

Number of red ball in beg = 13 balls

Find:

Probability [Both ball red without replacement]

Computation:

Probability of first red ball = Number of red ball in beg / [Total balls in beg]

Probability of first red ball = 13 / [6 + 3 + 13]

Probability of first red ball = 13 / 22

Probability of Second red ball = Number of remaining red ball in beg / [Total balls in beg without replacement]

Probability of Second red ball = [13 - 1] / [6 + 3 + 12]

Probability of Second red ball = 12 / 21

Probability [Both ball red without replacement] = [Probability of first red ball][Probability of Second red ball]

Probability [Both ball red without replacement] = [13/22][12/21]

Probability [Both ball red without replacement] = 26 / 77