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A bag contains 6 red marbles, 5 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 green?
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At the start, there are 6 + 5 + 7 = 18 marbles in the bag.
Of them, 7 marbles are green.
The probability that the first drawn marble is green equals .
After that, we have 17 marbles in the bag with 6 green marbles.
So, the probability that the first two drawn marbles are green equals .
Analyzing further in the same way, we find that the probability
that the first three drawn marbles are green equals
= reduce the fractions = = . ANSWER
Solved.