Question

⦁ Evaluate ⦁ 6! ⦁ 8P5 ⦁ 12C4

Answer 1

6! = 6 * 5 *4*3*2*1 =720

8p5 = 8*7*6*5*4 = 6720

12C4 = (12p4)/4! = (12*11*10*9)/4*3*2*1 = 495

Answer 2

N! = n(n-1)(n-2)(n-3)....
∴6! = 6×5×4×3×2×1 = 720
⁸P₅ = $\frac{8!}{(8-5)!} = \frac{8*7*6*5*4*3*2*1}{3*2*1} = 6720$
¹²C₄ = $\frac{12!}{4!*(12-4)!} = \frac{12*11*10*9*8*7*6*5*4*3*2*1}{4!*8!}$
       = $\frac{12*11*10*9*8*7*6*5*4*3*2*1}{4*3*2*1*8*7*6*5*4*3*2*1} = 495$