LUANDATO wrote:In jar A there are 3 white balls and 2 green ones, in jar B there is one white ball and three green ones. A jar is a randomly picked, what is the probability of picking up a white ball out of jar A?
A. 2/5.
B. 3/5.
C. 3/10.
D. 3/4
E. 2/3.
Generally:
AND means MULTIPLY.
OR means ADD.
P(picking Jar A) = 1/2. (Of the 2 jars, one is A.)
P(selecting a white marble from A) = 3/5. (Of the 5 marbles in A, 3 are white.)
Since we want to pick Jar A
and select a white marble from A, we MULTIPLY the probabilities:
1/2 * 3/5 = 3/10.
The correct answer is
C.
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