A bag contains 4 black, 5 red, and 6 pink balls. If 3 balls are selected one after the other without replacement, what is the probability that 3 red balls are chosen?

Question

asked Sep 18, 2017 216k views

2 Answers

Ngoan Nguyen · Answer 1 · 2017-09-24T22:56:00+0000

Answer:

The probability that 3 red balls are chosen is: 2.2%

Explanation:

A bag contains 4 black, 5 red, and 6 pink balls.

Total balls in the bag= 4+5+6= 15 balls in the bag

We need to know what is the probability that 3 red balls are chosen without replacement?

P_r=(R_b)/(T_b)*(R_b-1)/(T_b-1)*(R_b-2)/(T_b-2)

Where:

P_r: Probability that 3 red balls are chosen

R_b: Number of red balls

T_b: Number of total balls

$P_r=(5)/(15)*(5-1)/(15-1)*(5-2)/(15-2)\\P_r=(5)/(15)*(4)/(14)*(3)/(13)\\P_r=(1)/(3)*(4)/(14)*(3)/(13)\\P_r=(2)/(91)\\P_r=0.022$

P_r=0.022=2.2 %

The probability that 3 red balls are chosen is: 2.2%