A small seminar class consists of Anne, Bill, Cathy, Dan, Ellen, and Frank. The teacher has been told that 2 of them are from Indiana, 3 of them are from Michigan, and the other 1 is from Ohio. But the teacher does not know who is from which state. So the teacher decides to call on them one after another in alphabetical order and record which state each one is from until the teacher has found two (2) students from Indiana or has found a student from Michigan and a student from Ohio. How many overall outcomes are possible?

Well, it's not really a probability tree, but you can consider it as such.

This is a permutation/combination problem, until probability is involved :)

Okay, secondly, I find it a bit strange, the way the teacher in the problem works out which student is from where, in the sense that after what was told, the teacher, in many cases, wouldn't know where everyone is from... are you sure the question is complete? :confused:

I'll get you started. Suppose the first student (Anne) is from Michigan. You can draw a tree showing all possible paths that stop when either (a) two I's are found or (b) at least 1 M and an O are found. See the attached upside down tree diagram - starting from the top with an M, the tree branches to the next student being either an M, I, or O. If that second student is an O, then the tree stops as we have saitisfied the condition. Otherwise the tree must continue to branch as we go through the subsequent possibilities, with each sub branch coming to an end once we have satisfied the condition. If you count up the total number of branches given the first sudent is an M and you find there are 15 such possibilities.

Now repeat with the assumption that Anne is an I, and then that Anne is an O. Count up all the possible branches - what do you get?

A veterinarian has 8 dogs, 2 cats and 6 gerbils. Two animals are selcted at random. Find the probability that both are cats given that both are the same type of animal.

I AM TAKING AN INFINITE MATH CLASS THIS SUMMER AND TRYING TO FIGURE OUT MY HOMEWORK. IS THERE A WAY YOU COULD SHOW ME WHAT I MIGHT B DOING WRONG. Every time I DO THIS PROBLEM I COME UP WITH A DIFFERENT ANSWER..



A veterinarian has 8 dogs, 2 cats and 6 gerbils. Two animals are selcted at random. Find the probability that both are cats given that both are the same type of animal.[/QUOTE]

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Originally Posted by dutchess2012

i am taking an infinite math class this summer and trying to figure out my homework. Is there a way you could show me what i might b doing wrong. Everytime i do this problem i come up with a different answer..


This question seems like it would be a combination. However, i could ver well be wrong.

A veterinarian has 8 dogs, 2 cats and 6 gerbils. Two animals are selcted at random. Find the probability that both are cats given that both are the same type of animal.

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Thanks for your help in advance.

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Originally Posted by DUTCHESS2012

EVERYTIME i DO THIS PROBLEM i COME UP WITH A DIFFERENT ANSWER..

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Dutchess -
1. Please don't tag new problems onto old threads. Istead please submit a new question.
2. Please turn off your caps lock key - no need to shout!
3. Please show us what you've tried and where you're getting stuck. Have you tried applying Bayes' Theorem?