Question:
Given 5 flags of different colours, how many different signals can be generated if each signal requires the use of 2 flags, one below the other?
Given 5 flags of different colours, how many different signals can be generated if each signal requires the use of 2 flags, one below the other?
Updated On: Oct 21, 2023
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Solution and Explanation
Each signal requires the use of 2 flags.
There will be as many flags as there are ways of filling in 2 vacant places in succession by the given 5 flags of different colours.
The upper vacant place can be filled in 5 different ways by any one of the 5 flags following which, the lower vacant place can be filled in 4 different ways by any one of the remaining 4 different flags.
Thus, by multiplication principle, the number of different signals that can be generated is 5 x 4 = 20
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Permutation is the method or the act of arranging members of a set into an order or a sequence.
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Combination:
Combination is the method of forming subsets by selecting data from a larger set in a way that the selection order does not matter.
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