## anonymous one year ago 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.

1. misty1212

HI!!

2. misty1212

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

3. anonymous

hi again lol

4. anonymous

I kinda have a clue but im not sure

5. misty1212

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

6. anonymous

8

7. misty1212

ok and how many are blue?

8. anonymous

4

9. misty1212

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

10. anonymous

ummm

11. anonymous

4/8?

12. misty1212

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

13. misty1212

yeah $\frac{4}{8}$ except that you really want to say $$\frac{1}{2}$$ same thing

14. anonymous

oh ok

15. misty1212

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

16. anonymous

oh so it would be 1/2 again?

17. misty1212

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

18. misty1212

i.e. $\frac{1}{2}\times \frac{1}{2}$

19. misty1212

hope that is more or less clear

20. anonymous

Yeah makes sense

21. misty1212

k good