James started tutoring children several times a week. The first 2 weeks he had to purchase tutoring supplies and had losses of $40 and $65. The next 3 weeks he made a profit of $105, $70, and $140. At the end of the 6 weeks, he had a net profit of $252.
(a) Write an equation to find the profit or loss for the 6th week in this situation. Solve your equation. Was there a profit or a loss for that week? Show your work.
(b) What was James’s average profit or loss for the 6 weeks? Show your work.

Could I have a detailed explanation on how this would work? We don't know his original price, so how would we find it out and stuff? Im just a bit confused.