PrepSwift #15 Tickbox Quiz

[user2135]

I am confused about question 2, as Greg uses an example with an even probability to illustrate a case where the probability is uneven.

My approach:

Since marbles are drawn without replacement, each draw changes the composition of the remaining marbles, which affects the probabilities of subsequent draws.

• For the third draw (Quantity A) and the seventh draw (Quantity B), the probability of pulling a purple marble depends on the outcomes of all prior draws.

• If several purple marbles are drawn early, the probability of pulling a purple marble later (by the seventh draw) decreases. Conversely, if few or no purple marbles are drawn in the early pulls, the probability of pulling a purple marble later increases.

Since we do not know the outcomes of the previous draws in either case, we cannot determine whether Quantity A or Quantity B is greater, or if they are equal. Thus, the relationship cannot be determined

[cylverixxx]

Your question is exactly the same as the other user i helped previously, so maybe you could go through it here:

No Replacement Problem

Here, the assumption is that you pull all the marbles out. As for your question, assume that a random “draw” of 50 marbles looks like this: [‘B’ ‘G’ ‘R’ ‘G’ ‘R’ ‘G’ ‘G’ ‘G’ ‘B’ ‘G’ ‘R’ ‘R’ ‘R’ ‘B’ ‘R’ ‘B’ ‘B’ ‘B’ ‘R’ ‘B’ ‘R’ ‘B’ ‘R’ ‘R’ ‘G’ ‘B’ ‘G’ ‘R’ ‘R’ ‘R’ ‘B’ ‘B’ ‘B’ ‘R’ ‘G’ ‘B’ ‘G’ ‘G’ ‘G’ ‘G’ ‘B’ ‘B’ ‘G’ ‘B’ ‘R’ ‘R’ ‘B’ ‘R’ ‘G’ ‘G’] Now for each of these arrangement where the red marble is drawn third, you can imagine swapping the third and tenth component (the bolded components). […