The probability that Greg will not get to pick the cafe for either of the first two weeks' meetings is 4/9.
How to solve
The probability of Greg not getting to pick the cafe for the first week is 2/3 as there are two marbles out of three that are not green (Greg's color).
For the second week, if Greg hasn't picked the cafe in the first week, the probability that he won't pick it in the second week remains 2/3 because the marble is randomly drawn each week, and the previous week's selection doesn't impact the subsequent week's selection.
Therefore, the probability that Greg will not get to pick the cafe for either of the first two weeks' meetings is the probability that he doesn't pick the cafe for the first week and also doesn't pick it for the second week, which is
2/3 x 2/3 = 4/9
Hence, the probability is 4/9
The Complete Question
Reese, Greg, and Brad meet weekly for coffee, selecting their meeting place randomly using colored marbles: red (R) for Reese, green (G) for Greg, and blue (B) for Brad. Each week, they mix all three marbles in a bag and draw one to determine where they'll meet based on the person associated with the selected marble. What is the probability that Greg will not get to pick the cafe for either of the first two weeks' meetings?
Solution: