Question 253207
I assume that you do not replace. These are combination problems:
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(a) p (4 blue) = 6c0 * 7c4 * 4c0 * 5c0 / 22c4 = 35 / 7315 = .00478
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(b) P(2 pink and 2 white): 6c2 * 7c0 * 4c2 * 5c0 / 22c4 = 90 / 7315 = .0123
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(c) p(at least one is red). We don't want any red, so we choose all the others.
P(at least 1 red) = 17c4 * 5c0 / 22c4 = 2380 / 7315 = .3254