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put this solution on YOUR website!12P4 + 10P4 =
The number of permutations of n objects taken r at a time is:
nPr = n!/(n - r)!
We each separately and then add the results.
12P4 = 12!/(12 - 4)!
12P4 = 479001600/8!
12P4 = 479001600/40320
12P4 = 11,880
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10P4 = 10!/(10 - 4)!
10P4 = 3628800/6!
10P4 = 3628800/720
10P4 = 5040
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We now add both.
12P4 + 10P4 = 11,880 + 5040
12P4 + 10P4 = 16,920 ways