SOLUTION: I have worked out this problem, but it doesn't look right to me. Could you see what I have done wrong please. directions: Evaluate C(12,10) C(12,10)=12!/(12-10)! C(12,10)=12!/

Algebra ->  Probability-and-statistics -> SOLUTION: I have worked out this problem, but it doesn't look right to me. Could you see what I have done wrong please. directions: Evaluate C(12,10) C(12,10)=12!/(12-10)! C(12,10)=12!/      Log On


   

Question 169228: I have worked out this problem, but it doesn't look right to me. Could you see what I have done wrong please.
directions: Evaluate C(12,10)
C(12,10)=12!/(12-10)!
C(12,10)=12!/2!
C(12,10)=(1*2*3*4*5*6*7*8*9*10*11*12)/(1*2)
C(12,10)=3*1*5*6*7*8*9*10*11*12
C(12,10)=239,500,800
Will you please show me if I did something wrong. This looks like to big of a number
Thank you
Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
You forgot the "r!" in the denominator.
C(n,r) = n!/(r!(n-r)!)
C(12,10) = 12!/(10!(12-10)!)
C(12,10) = 12!/(10!(2)!)
C(12,10) = (11*12)/(1*2)
C(12,10) = 132/2
C(12,10) = 66