Two marbles are selectod randomly five a box containing 5 red, 7 white and 8 thore marbles one after the other withoet replacement. Find the probutility that (a) both are red; (b) one is white and the other is blase, (c) both are of the mane coloer
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The Deep Dive
To calculate the probabilities, we'll first determine the total number of marbles in the box, which is 5 red + 7 white + 8 blue = 20 marbles. (a) The probability that both marbles selected are red is: P(both red) = (5/20) * (4/20) = 1/20. (b) The probability that one is white and the other is blue can be calculated in two ways (either the first is white and the second is blue or vice versa): P(white first, blue second) = (7/20) * (8/20) = 56/400. P(blue first, white second) = (8/20) * (7/20) = 56/400. Total = 56/400 + 56/400 = 112/400 = 7/25. (c) The probability that both are of the same color takes into account the cases for red, white, and blue: P(both red) = 1/20 (calculated earlier), P(both white) = (7/20) * (6/20) = 21/400, P(both blue) = (8/20) * (7/20) = 56/400. So, P(same color) = 1/20 + 21/400 + 56/400 = 20/400 + 21/400 + 56/400 = 97/400. Thus: (a) P(both red) = 1/20, (b) P(one white and one blue) = 7/25, (c) P(both same color) = 97/400.