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Probability Question Solution

I decided I would try and make and solve a difficult probability question.

I feel my solution (if there even is one) is reasonably good, although I feel I am not at a high enough level or not to check if it actually is correct.

I will post the images of the question and my solution below:

Question

question.png

Solution
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Thanks :smile:
(edited 7 years ago)
answer.png120.6KB
Original post by some-student
I decided I would try and make and solve a difficult probability question.

I feel my solution (if there even is one) is reasonably good, although I feel I am not at a high enough level or not to check if it actually is correct.

Thanks :smile:


First off, you could check your solution using a small value of n and k. Work it though and see if it agrees with your formula.

Regarding your solution:

When the k'th sweet is chosen there won't be n-(k-1) sweets in each bag.
I'm not sure what you're doing after that; which admittedly isn't very far into your solution.
(edited 7 years ago)
Original post by ghostwalker
First off, you could check your solution using a small value of n and k. Work it though and see if it agrees with your formula.

Regarding your solution:

When the k'th sweet is chosen there won't be n-(k-1) sweets in each bag.
I'm not sure what you're doing after that; which admittedly isn't very far into your solution.


Thanks for the response :smile:

I decided to modify my wording of the question and the answer (but not change any principles) as I feel it may clear things up.

I'm not sure even if with my modifications my solution is right, but I think I worded the question incorrectly in terms of which sweet was to be drawn at that time.

And when you say you're not sure what I'm doing after that, does that mean I've got it completely wrong? (I wasn't expecting it to be right though :smile:)

Reworded Question:
q1.png

Reworded answer (in 3 parts):
Attachment not found

Attachment not found

ucles sending.jpg

Thanks :smile:
a1.png112.5KB
a2.png135.0KB
a3.png98.9KB
Original post by some-student

And when you say you're not sure what I'm doing after that, does that mean I've got it completely wrong? (I wasn't expecting it to be right though :smile:)



You've not defined what R and G are, which is why I'm not following it.

And you've not addressed my first point - there are not n-(k-1) sweets in each bag

Also the values of Ag,Br,BtA_g,B_r,B_t change each time you draw a sweet, and It's not clear to me that you're taking that into account.

And working through a test case for small values of n, would be useful as a check.
(edited 7 years ago)

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