Question

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?

Answer 1

5/15 * 4/14 * 3/13  = 2/91

Answer 2

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%