someone please help me out with this problem, thank you.

4. (30 points) Consider the following data for the water quality of two potential sources being evaluated for water supply for a community: The community proposes that it can be supplied by a blend of these two waters. It desires to have a blended chloride concentration below 150mg/L. For the supply of raw water, River A costs $20/m3 and River B costs $50/m3. However it costs more to treat water with a higher TOC according to this equation: cost(m3$)=10(TOC1)0.6 What is the most inexpensive mix of supply that meets the constraint