1. The problem statement, all variables and given/known data I attached the problem as file. 2. Relevant equations 3. The attempt at a solution I honestly do not know how to solve this problem. I have a test tomorrow, and this is really the only question that I am having difficulty with. I don't really know what mod means, especially in this context. I have tried to read the textbook, but it being rather convoluted, and me being constrained on time, was really quite futile.