please show help me, I will upvote

You are a brand new transportation manager for Volkswagen in the United States. Your region has 4 different customers and 3 different plants that make up the region. You have plants in Richmond, Baltimore, and Raleigh; each can produce 400 cars a week. Your customers are in Washington D.C., Philadelphia, Charleston, and Wilmington. Washington D.C. and Philadelphia both have demand of 350 cars per week, while Charleston and Wilmington have demand of 250 cars per week. Below is the route cost information. Q. Find the total transportation cost for both the northwest corner method and the intuitive lowest cost method. Q. Which method provides the cheapest solution, and how much cheaper is it \begin{tabular}{|l|l|l|l|l|} \hline & TO & \multicolumn{3}{|l|}{} \\ \hline FROM & Washington D.C. & Philadelphia & Charleston & Wilmington \\ \hline Raleigh & $15 & $17 & $9 & $3 \\ \hline Baltimore & $6 & $8 & $14 & $13 \\ \hline Richmond & $8 & $12 & $10 & $7 \\ \hline \end{tabular}