Question

There are 5 blue and 3 orange marbles in an urn. You will be picking without replacement.

What is the probability of picking a blue marble on the second pick if you don't know the color of the first pick?

Answer 1

answer and explain please..

Answer 2

why would it be a 5/8? when its on the second draw..

Answer 3

Its the part where " if you don't know the color of the first pick" is confusing me..

Answer 4

yeah you are right that is confusing me as well

Answer 5

lol

Answer 6

it cant be 5/8 for sure it can be 5/7

Answer 7

because we already picked one from the first draw right
OR it can be 4/7

Answer 8

so its 4/7 +5/7?

Answer 9

no

Answer 10

its either 5/7 or 4/7 but i dont know which one for sure actually it doesnt really specify which colour was taken out in the first try

Answer 11

it can be 5/7 if orange was taken out on the first try or it can be 4/7 if blue was taken out on the first try

Answer 12

o.o so i need a numberic answer.. o.o

Answer 13

@hamza_b23 I agree with on 4/7 or 5/7.

But I would guess that it's 4/7 because when you first picked it most likely would have been a blue.

Answer 14

- - miss_deva took u 5mins to type that LOl.

Answer 15

I was away for about 2 mins okay?! Lol

So it technically toke me 3. - -

Answer 16

lol

Answer 17

:P

Answer 18

Mr.@hamza_b23 what about this? What is the probability of picking a blue marble on the first pick, given that the 2nd pick is blue?

Answer 19

lol but yeah we cant write just 4/7 because the other option is still awailable you know theres hardly any information

Answer 20

by intuition 5/8

Answer 21

\[
\frac{3\ 5}{8\ 7}+\frac{5\
4}{8\ 7} =\frac 5 8
\]

Answer 22

it is not making sense if i do it by the conditional probability

Answer 23

Can you explain in words my solution in my post?

Answer 24

because look at it this way if the second one is blue and the first one is blue so to pick the first blue one is 5/8 obviously and then the next one is 4/7 you see?

Answer 25

sorry @eliassaab but how did you managae to get those numbers just curious

Answer 26

yes.

Answer 27

You either pick up a blue or orange in the first pick, then you pick a blue in the second pick. That is what I wrote up.

Answer 28

and lol 35 + 54 = 89 and 89/87 is not equal to 5/8 :s

Answer 29

i don't have the answer lol.

Answer 30

the answer is 5/8

Answer 31

yes

Answer 32

@hamza_b23 , It seems that you understand my solution since yours is exactly the same as mine.

Answer 33

i actually dont

Answer 34

Read on
A= Orange than Blue
B= Blue than Blue
We need
\[
P[A \cup B] = P[ A] + P[B] =
\frac{3\ 5}{8\ 7}+\frac{5\
4}{8\ 7}= \frac 5 8
\]

Answer 35

i am really sorry to break it down to you BUT (35 +54)/87 = 89/87 WHICH is greater than 1 HENCE not a probability and there is no way on earth that is EQUAL to 5/8 lol

Answer 36

\[P[A \cup B] = P[ A] + P[B] =
\frac 3 8 \frac 5 7+ \frac 5 8 \frac 4 7= \frac {15}{56}+ \frac {20}{56}=\frac {35}{56}
= \frac 5 8
\]

Answer 37

LOL O they are multiplied yes now it makes sense lol

Answer 38

Can you explain how you got 5/8 as an answer?

Answer 39

elisasaab ur smart.