We can use combination formula
[tex]C(n,r)=\frac{n!}{r!(n-r)!}[/tex]
we are given
C(7,4)
so, n=7 and r=4
now, we can plug this value
and we get
[tex]C(7,4)=\frac{7!}{4!(7-4)!}[/tex]
[tex]C(7,4)=\frac{7!}{4!\cdot \:3!}[/tex]
[tex]=\frac{7\cdot \:6\cdot \:5}{3!}[/tex]
[tex]=\frac{210}{6}[/tex]
[tex]C(7,4)=35[/tex].............Answer
