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Evaluate the combination:
7C4
A unique order or arrangement
nCr = | n! |
r!(n - r)! |
where n is the number of items
r is the unique arrangements.
7C4 2 | 7! |
4!(7 - 4)! |
n! = n * (n - 1) * (n - 2) * .... * 2 * 1
n! = 7!
7! = 7 x 6 x 5 x 4 x 3 x 2 x 1
7! = 5,040
(n - r)! = (7 - 4)!
(7 - 4)! = 3!
3! = 3 x 2 x 1
3! = 6
r! = 4!
4! = 4 x 3 x 2 x 1
4! = 24
7C4 = | 5,040 |
24 x 6 |
7C4 = | 5,040 |
144 |