Entropy and temperature of the system

Homework Statement

... Show that the entropy of the system in the microcanonical ensemble is

$$W = \frac{N!}{n!(N-n)!}3^n$$

and obtain an expression for the temperature of the system. ...
N = number of molecules
n = number of molecules in orthostate

The Attempt at a Solution

This question makes no sense, right? Because it says the entropy is W which is just a number, and entropy is in the units Joule/Kelvin