Re: From a jar containing 4 red and 2 white marbles, Lionel draw
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24 Feb 2023, 11:19
VERITAS PREP OFFICIAL SOLUTION:
Solution: 8/15. There are two paths to one of each color: Red, then White; or White, then Red. So you’ll need to calculate the probability of each sequence and add them together.
Red, then White: There’s a 4/6 probability of drawing Red first, and then there will be 2 White left to draw from the remaining 5 marbles. So that’s a probability of 2/3 * 2/5 for a total of 4/15.
White, then Red: there’s a 2/6 probability of drawing White first, at which point there would be 4 Red left to draw from the remaining 5 marbles. That’s a probability of 1/3 * 4/5 = 4/15. Add together the two probabilities to get the total probability of one of each, and you get a total of 8/15.