6!/2!3!

Question

For this problem, I did 6*5*4*3*2*1/2*1*3*1 for the answer 729/6=120

Answer 1

No , you messed up the denominator.

I will assume you meant 6!/(2!3!)
= 6*5*4*3*2*1/(2*1*3*2*1)
= 720/(2*6) = 720/12 = 60

Answer 2

And for c(8,6),

I did 8!/(8-6!) =8!/2! = 8*7*6*5*4*3*2*1/2*1 =40320/2=20160 but I think it is wrong.

Answer 3

C(n,r) = n!/[ r!(n-r)! ]
= 8! / [6!(2!)] = 8*7 / 2 = 4*7 = 28