In the first urn there are 3 white and 4 black balls in the second 2 white and 3 black balls in the third 6 white and 2

| August 4, 2021 | education

In the first urn there are 3 white and 4 black balls in the second 2 white and 3 black balls in the third 6 white and 2 black balls. a ball is taken out at random from an urn chosen at random. what is the probability that it is white?

Consider the choice of urns, since they are equally probable, then the probability of choosing one of the urns is 1/3.

The probability of choosing a white ball (out of three) from the first urn with ten possible ones is:

P (A) = 3/7.

The probability of choosing a white ball (out of two) in the second urn with five possible is equal to:

P (B) = 2/5.

The probability of choosing a white ball (out of six) in the third urn with eight possible is equal to:

P (C) = 6/8 = 3/4.

Using the formula for total probability, we get:

P (D) = (1/3) * (3/7) + (1/3) * (2/5) + (1/3) * (3/4) = 221/420.



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