Question 1182239: a. A bag contains 8 blue marbles, 9 yellow marbles, and 10 red marbles.
If a marble is drawn from the bag, and another marble is drawn, what is the probability of drawing first a blue marble and then a red marble?
_______
b. A bag contains 9 white marbles, 10 red marbles, and eight yellow marbles.
If two different marbles are drawn from the bag, what is the probability of drawing first a white marble and then a yellow marble?
_______
Round to 4 decimal places
Found 2 solutions by mathmate, ikleyn:
Answer by mathmate(429)   (Show Source):
You can put this solution on YOUR website! Given:
a. 8B, 9Y, 10R marbles.
Two marbles are drawn (with replacement)
Find P(BR)
b. 9W, 10R, 8Y marbles.
Two marbles are drawn (without replacement).
Find P(WY)
Solution, using the multiplication rule:
(a) total 27 marbles.
P(BR) = (8/27)*(10/27) =80/729 (with replacement)
= 0.1097 (to four decimal places)
(b) total 27 marbles.
P(WY) = (9/27)*(8/26) = 4/39 (without replacement)
= 0.1025 (to four decimal places)
Answer by ikleyn(52814)  (Show Source):
You can put this solution on YOUR website! .
a. A bag contains 8 blue marbles, 9 yellow marbles, and 10 red marbles.
If a marble is drawn from the bag, and another marble is drawn, what is the probability
of drawing first a blue marble and then a red marble?
_______
b. A bag contains 9 white marbles, 10 red marbles, and eight yellow marbles.
If two different marbles are drawn from the bag, what is the probability
of drawing first a white marble and then a yellow marble?
_______
Round to 4 decimal places
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For problem (a), the probability is P =  = 0.1140 (rounded). ANSWER
For problem (b), they ask about the CONDITIONAL probability
P = P(WY | the two marbles are of DIFFERENT colors).
It is
P =  .
The numerator is P(WY) =  = 0.102564.
The denominator is 1 - P(WW) - P(RR) - P(YY) =  = 0.689459
Then the ratio P = =  = 0.1488 (rounded as requested). ANSWER
Solved (correctly).
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To tutor @mathmate and to the visitor :
The problem says NOTHING about replacement/replacements,
which means, by DEFAULT, NO REPLACEMENT.
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