The Razorback t-shirt shop makes $ w dollars off each t-shirt sold. During the Arkansas and Texas tech game they made $ w0 by selling t-shirts. How many t-shirts did they sell?
Let's say that the shop sold x t-shirts during the game. 

Then we know that: 

w0 = w*x 

or 

x = w0/w. 

Thus, if we know w and w0, we can calculate x.