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Question
How many different signals can be made from 4 red, 2 white and 3 green flags by arranging all of them vertically on a flagstaff?
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Solution
We have to arrange 9 flags, out of which 4 are of one kind (red), 2 are of another kind (white) and 3 are of the third kind (green).
∴ Total number of signals that can be generated with these flags =\[\frac{9!}{4!2!3!}\]= 1260
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