Answer:
typically, this problem doesn't include any value for n cuz! but solving using portion, the answer is 59/19
or 3.11
Explanation:
proofing my ans:
(n-1)!/n-3! = 20
cross multiply
20(n-3)=n-1
20n -60=n-1
20n-n=-1+60
19n=59
divide both sides of the equation by 19
n = 59/19
decimal form is 3.11