# Advanced Probability

3 Questions

QUESTION 1 of 3

Hi Professor,

For Now You Try It! 3.8 Advanced Probability I don't understand number 3. I am confused between what is meant by the numbering of the marble compared to the color of the marble and how to put it in the combination formula.

A box of numbered marbles has 12 red, 12 blue, 12 green, and 12 yellow marbles. The

marbles for each color are numbered from 1 to 12. That is there is a unique number on

each marble, so no marble is exactly the same as any other marble in the box. When

reaching into the box to randomly draw five marbles without replacement, what is the

probability of getting exactly four marbles of the same color (note: the numbers matter

but the order does not)?

Also, I wanted to know when I took the Sample Test for number 3 you pointed out that it is without replacement because the probability is 3/120 which is less than 5%. On the test would you point that out or do would we have to figure it out by dividing the sample by the population?

3. A bin at a local big box store has 120 discounted packs of batteries of which 9 are old and contain batteries that no longer work. If three of the packs of batteries are randomly selected for purchase, what is the probability that all of the packs of batteries are good ones (treat this problem as if it involves selection with replacement since 3/120 is less than 5%)?

Thank you.

QUESTION 3 of 3

Good evening Professor,

I am having trouble with Example 58.5. I am not sure where the 4C4 or for that matter the rest of the combinations are coming from, when trying to solve the problem for the 52 card deck question

Thanks in advance Alex Morales