On Father's Day, Diana wanted to buy a shirt and a tie for her father. 4 ties and 5 shirts cost $375. A shirt cost $12 more than a tie. What is the cost of a tie?

t=35

The Question says: 4t + 5s = 375

The Question also says: s = t+12

Now, we can substitute the value of s and our equation will become:

4t + 5(t+12) = 375.

We can easily solve this:

4t + 5(t+12) = 375

4t + 5t + 60 = 375

9t = 375-60

9t = 315

t = 35

Therefore, a tie cost $35.