A bag contains 5 red marbles, 8 blue marbles and 7 green marbles. If two marbles are drawn out of the bag, what is the exact probability that both marbles drawn will be blue?Answer:
Q. A bag contains 5 red marbles, 8 blue marbles and 7 green marbles. If two marbles are drawn out of the bag, what is the exact probability that both marbles drawn will be blue?Answer:
Calculate Total Marbles: Determine the total number of marbles in the bag. The bag contains 5 red marbles, 8 blue marbles, and 7 green marbles. To find the total, we add these numbers together. 5 red +8 blue +7 green =20 total marbles.
First Blue Marble Probability: Calculate the probability of drawing the first blue marble.The probability of drawing a blue marble on the first draw is the number of blue marbles divided by the total number of marbles.Probability of first blue marble = Number of blue marbles / Total number of marbles = 208.
New Total Marbles: Determine the new total number of marbles after one blue marble has been drawn.After drawing one blue marble, there is one less blue marble and one less marble in total.New total number of marbles = 20−1=19 marbles.
Second Blue Marble Probability: Calculate the probability of drawing a second blue marble after the first has been drawn.Now, there are 7 blue marbles left and 19 marbles in total.Probability of second blue marble = Number of blue marbles left / New total number of marbles = 197.
Consecutive Events Probability: Calculate the probability of both events happening consecutively.To find the probability of both marbles being blue, we multiply the probability of the first event by the probability of the second event.Probability of both blue marbles = Probability of first blue marble × Probability of second blue marble = (8/20)×(7/19).
Simplify Probability: Simplify the probability.(208)×(197)=(52)×(197)=9514.
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