Question

A bag has 1 red marble, 4 blue marbles, and 3 green marbles. Peter draws a marble randomly from the bag, replaces it, and then draws another marble randomly. What is the probability of drawing 2 blue marbles in a row? Explain your answer.

Answer 1

HI!!

Answer 2

you got a clue or you want to go real slow?

Answer 3

hi again lol

Answer 4

I kinda have a clue but im not sure

Answer 5

ok so lets take it step by step
how many marbles are in the bag total?

Answer 6

8

Answer 7

ok and how many are blue?

Answer 8

4

Answer 9

ok good, so what is the probability that the first one selected is blue?

Answer 10

ummm

Answer 11

4/8?

Answer 12

make a guess, if you are wrong i will tell you

Answer 13

yeah
\[\frac{4}{8}\] except that you really want to say \(\frac{1}{2}\) same thing

Answer 14

oh ok

Answer 15

now you put the marble back (it says that) so you still have 4 blue marbles in the bag and 8 total

Answer 16

oh so it would be 1/2 again?

Answer 17

yes
and for them both to happen, blue and then blue again, the probability is the product of those two

Answer 18

i.e.
\[\frac{1}{2}\times \frac{1}{2}\]

Answer 19

hope that is more or less clear

Answer 20

Yeah makes sense

Answer 21

k good