Answer:
n=12
Step-by-step explanation:
lol we meet again
just use the permutation formula for this one.
n!/(n-3)!=1320
[n×(n-1)×(n-2)×(n-3)!]/(n-3)!=1320
n(n-1)(n-2)=1320
(n²-n)(n-2)=1320
n³-3n²+2n-1320=0
