Question 1192042: A box contains 20 balls that are exactly alike except that 10 are red, 6 are blue, and 4 are black. (a) If a single ball is drawn from a box, what is the probability tat it is red? (b) If a single ball is drawn from the box, what is the probability that it is blue or black? (c) If instead two balls are drawn from the box at the same time, what would be the probability that both are black?
Answer by Boreal(15235)   (Show Source):
You can put this solution on YOUR website! a. 10 red/20 overall probability is 0.5
b. blue or black are also 10 balls, so the answer is also 0.5
c. prob. first is black is 4/20 and second one also black is 3/19. The answer is their product, 12/380, which may be reduced or put into decimal form.
It is also 4C2*/20C2=6/190, the reduced form of the above
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