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A bag contains 7 red marbles, 12 orange marbles, 18 yellow marbles, and 5 purple marbles. A marble is drawn at random from the bag. What is the probability that the marble drawn will not be orange?

1 Answer
Jun 17, 2016

Answer:

#5/7#

Explanation:

There are 42 marbles in the bag.
When one marble is taken out at random, in terms of orange, there are only two possible outcomes:
either the marble IS orange, or it ISN'T.

There are 12 marbles which ARE orange, which means that the rest are NOT orange. #(42-12 = 30)#

#P("not orange") = 30/42 = 5/7#

This can also be shown as;

#P("an event NOT occurring") = 1 - P("DOES occur")#

#P("orange") = 12/42 = 2/7#

#P("not orange") = 1 - 2/7 = 5/7#