Posted on June 4, 2010.
Jamal has 8 beans of red frost and 9 beans of green frost in a bag. It attains in his bag and goes out with 4 jel?(One) which is the probability that the frost beans in his hand are all red one?
(B) which is the probability that the frost beans in his hand are all the same color (all red or all green)?
(C) which is the probability that 3 are red and 1 is green?
(one)
Of the 8 red one, choose 4; of the 9 greens to choose 0. The probability is
(8C4) (9C0) / (17C4) = [8! /(4! 4! )][9! / (9! 0)]! / [17! / (4! 13!)] = (70/1) /2380 = 1/34
(b)
Do the same calculation as in (one) but for 4 greens, then to add your result to has it for result (one) (the two exits are exclusive mutuelment, therefore you add the probabilities)
(c)
(8C3) (9C1) / (17C4) = 56*9/2380 = 504/2380 = 18/85
