Question

A bag contains 10 red marbles, 15 yellow marbles and 5 green marbles. What is the probability of drawing a red or green marble from the bag?

Answer 1

Probability of red*Probability of green

Answer 2

They're mutually exclusive events, so you would add the probabilities.\[
\Pr(X=\text{red}) + \Pr(X=\text{green})
\]

Answer 3

Since you draw only a single marble, it's not possible to draw both a red and green marble at the same time. This is what makes the mutually exclusive.

Answer 4

In either case, there are \(10+15+5=30\) total marbles.

Answer 5

\[
\Pr(X=\text{red}) = \frac{\text{number of red marbles}}{\text{total number of marbles}}
\]

Answer 6

so it would be 10/5

Answer 7

correct?

Answer 8

No

Answer 9

Since \(5\) is not the total number of marbles.

Answer 10

ohh so it would be 10/30

Answer 11

Well, that is correct for pulling 1 red marble, so you're partially done.

Answer 12

and for the pulling of a green marble it would be 5/30, correct?

Answer 13

Yes.

Answer 14

ok thanks soooo much

Answer 15

What is the final answer?

Answer 16

the answer choices were, A. 1/2, B. 1/4, C. 1/6, & D. 1/8

Answer 17

I choose C

Answer 18

becuase 5/30 simplified is 1/6

Answer 19

correct?

Answer 20

No, you need to add them. That gives you: \[
\frac{10}{30} + \frac{5}{30} = \frac{15}{30} = \frac 12
\]