A bag contains 5 red marbles, 4 blue marbles and 7 green marbles. If three marbles are drawn out of the bag, what is the exact probability that all three marbles drawn will be red?Answer:
Q. A bag contains 5 red marbles, 4 blue marbles and 7 green marbles. If three marbles are drawn out of the bag, what is the exact probability that all three marbles drawn will be red?Answer:
Determine total number of marbles: Determine the total number of marbles in the bag.The bag contains 5 red marbles, 4 blue marbles, and 7 green marbles. So, the total number of marbles is 5+4+7=16 marbles.
Calculate probability of drawing one red marble: Calculate the probability of drawing one red marble. The probability of drawing one red marble is the number of red marbles divided by the total number of marbles, which is 165.
Calculate probability of drawing second red marble: Calculate the probability of drawing a second red marble after one has already been drawn.After drawing one red marble, there are now 4 red marbles left and 15 marbles in total. The probability of drawing a second red marble is now 154.
Calculate probability of drawing third red marble: Calculate the probability of drawing a third red marble after two have already been drawn.After drawing two red marbles, there are now 3 red marbles left and 14 marbles in total. The probability of drawing a third red marble is now 143.
Calculate probability of all three events: Calculate the probability of all three events happening in sequence (drawing three red marbles in a row).The probability of all three events happening in sequence is the product of the probabilities of each event. This is calculated as (165)×(154)×(143).
Perform multiplication to find exact probability: Perform the multiplication to find the exact probability.The exact probability is (165)×(154)×(143)=(16×15×145×4×3)=336060.
Simplify fraction to lowest terms: Simplify the fraction to its lowest terms.The fraction 336060 can be simplified by dividing both the numerator and the denominator by the greatest common divisor, which is 60. So, 336060 simplifies to 561.
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