Question

PLEASE HELP!! SHOW WORK!!A bag has five red marbles, six blue marbles, and four black marbles. What is the probability of picking a blue marble, replacing it, and then picking a red marble?

a)8/75
b)3/5
c) 2/15
d)4/45

Answer 1

c) 2/15

Explanation:

The total number of marbles

5+6+4 = 15 marbles

First we find the probability of a blue marble. There are 6 blue marbles

P(blue) = blue/total = 6/15 = 2/5

We put the marble back so there are still 15 marbles in the bag

Then we find the probability of a red marble. There are 5 red marbles

P(red) = red/total = 5/15 = 1/3

Since we put the marble back, they are independent events, and we can multiply the probabilities.

P(blue, then red) = 2/5*1/3 = 2/15