Models & Qualitative Behavior · Challenge problem

Tank A holds $100$ L of water with $200$ g of dissolved salt; tank B holds $100$ L of pure water. Pure water flows into A at $5$ L/min, the well-mixed contents of A flow into B at $5$ L/min, and B drains at $5$ L/min. What is the largest amount of salt (in grams) that tank B ever holds? Give an exact answer.