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Question
Set A has 3 elements and the set B has 4 elements. Then the number of injective mappings that can be defined from A to B is ______.
Options
144
12
24
64
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Solution
Set A has 3 elements and the set B has 4 elements. Then the number of injective mappings that can be defined from A to B is 24.
Explanation:
The total number of injective mappings from the set containing 3 elements into the set containing 4 elements is 4P3 = 4! = 24.
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