Question

In a box of 6 red and 4 green balls, 3 balls are selected at random without replacement. Find the probability distribution of the number of red balls. *

Answer 1

Box contains 6 RED balls and 4 GREEN balls , so there are 10 balls in a box

We have to draw 3 balls from the box . Let x (=0,1,2,3) be the number of red balls drawn.

p(x=0) = * / = 1*4 / 120 = 1/30 = 0.0333

p(x=1) = * /   = 6* 6 / 120 = 3/10 = 0.3

p(x=2) = * / = 15 * 4 /120 = 1/2 = 0.5

p(x=3) = * /   = 20 * 1 / 120 = 1/6 = 0.1666

Probability distribution of the number of red balls (x) drawn from the box of 10 balls.

Probability distribution of x

x	0	1	2	3
p(X=x)	1/30	3/10	1/2	1/6