There are two closed boxes, filled with red and white marbles. One of the boxes is 2/3 red and the other is 2/3 white.

You're allowed to sample 5 marbles from the first box, and 30 from the second. As a result, you get 4 red and 1 white marble from the first box, and 20 red and 10 white from the second. Which is more likely to be the one with majority red marbles?

Assume the two boxes contain the same number of marbles.

Okay, kinda cheezy, but:

Since the problem doesn't state the number of marbles in the boxes, we may presume it doesn't matter. So, assume the number is 30 (or any multiple of 3 less than 60). Finding 20 red marbles in the second box indicates that it ihas the majority red.