Answer:
35
Step-by-step explanation:
nCr = n! ÷ r!(n - r)!
7C3 = 7! ÷ 3!(7 - 3)!
n! = 7!
7! = 7 x 5 x 4 x 3 x 2 x 1
7! = 5,040
r! = 3!
3! = 3 x 2 x 1
3! = 6
(n - r)! = (7 - 3)!
(7 - 3)! = 4!
4! = 4 x 3 x 2 x 1
4! = 24
7C3 = 5,040 ÷ 6 x 24
7C3 = 5,040 ÷ 144
7C3 = 35
