Question

A bag contains 4 red and 6 black balls . Three balls are drawn at random . Then the probability distribution of the number of red balls is

Answer 1

there are 4 red and 6 black balls .

probability of red ball is ………

all are red..........

4C3 ÷ 10C3
= 4 ÷ 120
=1/30

2 red ball..........

=[4C2 + 6C1] ÷[10C3]
=[6 + 6] ÷ [120]
=12 ÷ 120
=1/10
=0.10

1red ball………

=[4C1 + 6C2] ÷ [10C3]
=[4 + 15] ÷ [120]
=19/120
=.158333…….

no red ball…….

here no red ball means all are black ball.

= 6C3 ÷ 10C3
= 20 ÷ 120
= 1/60
= 1.16666…………