Problem: Suppose you are a Laboratory Manager at Toronto Research Chemicals, in charge of supplying of chemicals for project leads. As such, you will be maintaining a stock solution and provide working solutions to respective projects. You have ordered a chemical, "chitosan" (Deacetylated chitin, Poly D-glucosamine), from Sigma-Aldrich and reconstituted to 0.15 M stock solution. The following is a simplified design to make different working concentrations of Chitosan solutions requested by 3 groups. The volume of stock solution needed to make solution in Tube P and Tube Q respectively.