A bag contains 7 white balls and 8 red balls. Construct a probability tree to determine the probability that if 2 balls are drawn,with replacement, the first ball is red R and the second is white W.
A) Pr(R first ∩ W second) =
B) Pr(R first ∩ W second) =
C) Pr(R first ∩ W second) =
D) Pr(R first ∩ W second) =
E) Pr(R first ∩ W second) =

Question

A bag contains 7 white balls and 8 red balls. Construct a probability tree to determine the probability that if 2 balls are drawn,with replacement, the first ball is red R and the second is white W. ​
A) Pr(R first ∩ W second) = 
B) Pr(R first ∩ W second) = 
C) Pr(R first ∩ W second) = 
D) Pr(R first ∩ W second) = 
E) Pr(R first ∩ W second) =

Quizplus · Accepted Answer

The probability tree for selecting two balls with replacement is as follows:

R                        W
         /       \                 /       \
        8/15    7/15             8/15     7/15
        /           \            /            \
       R           W          R            W

To find the probability of getting a red ball first and a white ball second, we multiply the probabilities along the branch for R followed by W:

P(R first ∩ W second) = (8/15) x (7/15) = 56/225

Thus, the best choice is D).

A Bag Contains 7 White Balls and 8 Red Balls