Question

A bag has 7 red marbles, 8 blue marbles and 3 black marbles. What is the probability of picking a blue marble, replacing it, and then picking a black marble?

Would my answer me 2/27?

Answer 1

@morganchavez

Answer 2

Im just suppose to multiply 8/18 and 3/18, right?

Answer 3

no its 2/18

Answer 4

Care to walk me through it so I know how to do the others like it?

Answer 5

ok add all the amount of marbles so 8+7+3 and it equals 18
so then since ur taking one out ur probability of taking out a blue marble is 8/18 then u replace it so then ur probability of taking a black marble out is 3/18

Answer 6

do u have multiple choice if so post the choices

Answer 7

2/27
14/81
7/108
1/9

Answer 8

I thought I just multiplies the 2 probabilities together but I guess I was wrong, how do you do it?

Answer 9

were are u getting 27 from?

Answer 10

No those are the choices I have to chose from.

Answer 11

Wait whoops hold Up I know what you mean, duh

Answer 12

I got 2/27 from multiply 8/18 and 3/18 together.

Answer 13

@morganchavez

Answer 14

U DONT MULTILY u add so it would be 12/18

Answer 15

keep denominator same and add top

Answer 16

wouldnt that be 11/18 then? Where do you get 12/18 from?

Answer 17

YES 11 IM SOOO SORRY ive been adding 8+3 wrong all day i apolagize

Answer 18

so it would be 11/18

Answer 19

But the choices for answer i have are
2/27
14/81
7/108
1/9

Answer 20

hang on my luck i probably did it wrong i apolagize what grade r u in ?

Answer 21

11th haha. This is a review and its a pain :/

Answer 22

yass its 2/27 u were right i apolagize im in 11 grade i havent done this in a while i was thinking of another form i was taought ......XD omg yup so now u know how i feel lol

Answer 23

@iGreen Help us please xD

Answer 24

there are diff ways to get diff answers for this type of stuff and i ws thinking of a diff problem i sorry

Answer 25

Its alright, but how did you get 2/18 before? Im curious because thats a possible answer :/