Question 550439
C(n,r) = (n!)/(r!(n-r)!)


C(30,2) = (30!)/(2!*(30-2)!)


C(30,2) = (30!)/(2!*28!)


C(30,2) = (30*29*28!)/(2!*28!)


C(30,2) = (30*29)/(2!)


C(30,2) = (30*29)/(2*1)


C(30,2) = (870)/(2)


C(30,2) = 435


So the answer is choice C