If four marbles are picked at random, what is the probability

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Direction: Study the given information carefully and answer the question that follow.
An urn contains 6 red, 4 blue, 2 green and 3 yellow marbles.

If four marbles are picked at random, what is the probability that at least one is blue ?

1. 4/15
2. 69/91
3. 11/15
4. 22/91

Correct Option: D

Probability that none is blue from four marbles
= ^{15 - 4}C₄ / ¹⁵C₄
= ¹¹C₄ / ¹⁵C₄ = 22/91

So, probability that at least one is blue from four marbles = 1 - 22/91 = 69/91