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Question
Mark the correct alternative in the following question:
If the set A contains 7 elements and the set B contains 10 elements, then the number one-one functions from A to B is
Options
10C7
10C7\[\times\] 7!
710
107
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Solution
As, the number of one-one functions from A to B with m and n elements, respectively = nPm = nCm
\[\times\] m!
So, the number of one-one functions from A to B with 7 and 10 elements, respectively = 10P7 = 10C7 \[\times\]7!
Hence, the correct alternative is option (b).
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