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Consider a collection of envelopes consisting of 1 red,2 blue,3 green, and 2 yellow .
If three envelopes are selected at random, without replacement,
determine the probability that they are all green envelopes.
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Total envelops = 1 + 2 + 3 + 2 = 8.
The probability under the problem question is P = = = = . ANSWER.
The formula is SELF-EXPLANATORY.
Solved and explained.