A bag contains 4 red marbles, 3 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 4 red marbles, 3 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:
Determine total number of marbles: Determine the total number of marbles in the bag.The bag contains 4 red marbles, 3 blue marbles, and 7 green marbles. So, the total number of marbles is 4+3+7.
Calculate total number: Calculate the total number of marbles.4 red + 3 blue + 7 green = 14 marbles in total.
Determine probability of first blue marble: Determine 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 = 143.
Determine new total number: Determine the new total number of marbles after one blue marble is drawn. After drawing one blue marble, there are 2 blue marbles left and the total number of marbles is now 13 (since one marble has been removed and not replaced).
Determine probability of second blue marble: Determine the probability of drawing the second blue marble. The probability of drawing a second blue marble after the first one has been drawn is the number of remaining blue marbles divided by the new total number of marbles. Probability of second blue marble = Remaining blue marbles / New total number of marbles = 132.
Calculate combined probability: Calculate the combined probability of both events happening consecutively.The probability of both events (drawing two blue marbles in a row) is the product of the probabilities of each individual event.Combined probability = Probability of first blue marble × Probability of second blue marble = (143)×(132).
Perform multiplication: Perform the multiplication to find the exact probability.Combined probability = (143)×(132)=1826.
Simplify fraction: Simplify the fraction to its lowest terms. 1826 can be simplified by dividing both the numerator and the denominator by the greatest common divisor, which is 6.1826=30.31.
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