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

@Nnesha

Answer 2

oky so i guess \[\rm \frac{ blue~marbles }{ total ~number~of marbles }\]

Answer 3

ahhh i'm not good 't probability stuff ?/>

Answer 4

@jim_thompson5910

Answer 5

ITS OK THANKS

Answer 6

@Nnesha you're on the right track

Answer 7

Would it be 2/8

Answer 8

you need to figure out how many blue marbles there are, out of how many total

probability of picking blue = (# of blue)/(# total)

since replacements are made, this means that the probability does not change on the second draw

Answer 9

probability of picking 2 blue = (probability of picking 1 blue)*(probability of picking 1 blue)

Answer 10

so im kinda lost...so it would be 2= 1x1?

Answer 11

we have 4 blue out of 8 total

so you agree that the probability of picking one blue is 4/8 = 1/2 right?

Answer 12

yes

Answer 13

the probability of picking 2 blue is equal to


P(2 blue) = P(1 blue AND 1 blue)
P(2 blue) = P(1 blue)*P(1 blue)
P(2 blue) = (1/2)*(1/2)
P(2 blue) = (1*1)/(2*2)
P(2 blue) = 1/4

Answer 14

this rule only works because replacements are made and each drawing is independent

Answer 15

OK so what should i write down? @jim_thompson5910

Answer 16

Basically those steps and the answer. But in your own words and format that's unique to you. Hopefully you see how I got that answer?

Answer 17

yes thank u!

Answer 18

you're welcome

Answer 19

thanks @jim_thompson5910 o^_^o