Question 574593
C(n,r) = (n!)/(r!(n-r)!)


C(5,3) = (5!)/(3!*(5-3)!)


C(5,3) = (5!)/(3!*2!)


C(5,3) = (5*4*3!)/(3!*2!)


C(5,3) = (5*4)/(2!)


C(5,3) = (5*4)/(2*1)


C(5,3) = (20)/(2)


C(5,3) = 10



So C(5,3) or 5 C 3 is <font color="red">10</font>