4.) a bag contains 10 red marbles and 5 blue marbles. you randomly select 3 marbles from the bag. what is
the probability that all 3 marbles are blue when (a) you replace each marble before selecting the next one and
(b) you do not replace each marble before selecting the next one?

a) 1/27

b) 2/91

Step-by-step explanation:

A bag contains 10 red marbles and 5 blue marbles (15 marbles in total). You randomly select 3 marbles from the bag.

a) You replace each marble before selecting the next one.

The probability of selecting one blue marble is

then the probability that all 3 marbles are blue is

b) You do not replace each marble before selecting the next one. Each time the number of blue marbles decreases by 1 and the total number of marbles decreases by 1 too. So the probability that all 3 marbles are blue is

idk

step-by-step explanation:

use that smart brain