Probability question..Please help!

[Dopamine_Fiend]

I have a bag of 300 unique marbles.

I take out 40 marbles, look at them, then put them back in the bag.

I repeat this 9 times.

What is the likely amount of unique marbles I have seen?

 

[Deleted member 4993]

I have a bag of 300 unique marbles.

I take out 40 marbles, look at them, then put them back in the bag.

I repeat this 9 times.

What is the likely amount of unique marbles I have seen?

Please show us what you have tried and exactly where you are stuck.

Please follow the rules of posting in this forum, as enunciated at:

https://www.freemathhelp.com/forum/threads/read-before-posting.109846/#post-486520

Please share your work/thoughts about this assignment.

You say - I repeat this 9 times. Does that mean you have pulled ( 40 marbles) total 10 times including the first time?

 

[Dopamine_Fiend]

Well this isn't an assignment or anything like that, it's a scenario I thought of myself. The problem is, I am unsure of what probability formula to use in order to deduce an estimate of the number of different unique marbles I've seen and exclude the number of repeated marbles I've taken out already from previous pull outs.

I believe the way to solve this is to apply a formula that can determine the "chance" a marble would be repeated if pulled out again and utilise that logic.

And for your last point, you are correct I mean that I've done this process a total of 10 times.

Many thanks.

 

[Deleted member 4993]

Well this isn't an assignment or anything like that, it's a scenario I thought of myself. The problem is, I am unsure of what probability formula to use in order to deduce an estimate of the number of different unique marbles I've seen and exclude the number of repeated marbles I've taken out already from previous pull outs.

I believe the way to solve this is to apply a formula that can determine the "chance" a marble would be repeated if pulled out again and utilise that logic.

And for your last point, you are correct I mean that I've done this process a total of 10 times.

Many thanks.

I have not done this problem - I am just thinking.

Can you figure out the probability of pulling at least 1 "non-unique" marble during the second pull.

 

[pka]

I have a bag of 300 unique marbles.
I take out 40 marbles, look at them, then put them back in the bag.
I repeat this 9 times.
What is the likely amount of unique marbles I have seen?

Well this isn't an assignment or anything like that, it's a scenario I thought of myself. The problem is, I am unsure of what probability formula to use in order to deduce an estimate of the number of different unique marbles I've seen and exclude the number of repeated marbles I've taken out already from previous pull outs.

This is a perfect example of why amateurs should not makeup and post questions.
I encourage the study of probability by all. There are so many good "problem books" so why makeup a question that is so complicated that most professionals would not consider working on it for fun?