Answer:
4845
Step-by-step explanation:
Given 20C4 this means ₂₀C₄
Apply the formula for combinations without repetition
[tex]nCr=\frac{n!}{(n-r)!.r!}[/tex]
where
n is the number of things to choose from and r is what you choose from them
Given that ;
n=20
r=4
n-r=20-4=16
Insert values in the equation
[tex]20C4=\frac{20!}{16!*4!} \\\\\\=\frac{16!*17*18*19*20}{16!*4!} \\\\\\=\frac{17*18*19*20}{1*2*3*4} \\\\\\=17*19*15\\\\\\=4845[/tex]