Find the number of different signals that can be generated by arranging at least 2 flags in order (one below the other) on a vertical staff, if five different flags are available.
Given:5 Flags
Way of generating signal using 2 different flags =5P2 (way of selecting 2 things out of 5 things with considering arrangement.)
Way of generating signal using 3 different flags =5P3
Way of generating signal using 4 different flags =5P4
Way of generating signal using 5 different flags =5P5
So total number of ways =5P2 + 5P3 + 5P4 + 5P5
=20 + 60 + 120 + 120
=320
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