Need step-by-step details on how to solve this problem below. Thank you.

13 Marc Hernandez's construction rm currently has three projects in progress. Each requires a specic supply of gravel. There are three grayel pits avail able to provide for Hemandez's needs, but shipping costs differ from location to location. The following table summarizes the transportation costs: T TDNNAGE FRDM .103 l J DB 2 JOB 3 ALLOWANCE Central pit $9 $ 3 $ '1' 3,011} Rock pit $7 $11 $ 6 4,0II} Acme pit $4 $ 3 $12 6,011} Job requirements 2,511] 3,750 4,350 (tons) (a) Determine Hernandez's optimal shipping quanti ties so as to minimize total transportation costs. (b) It is the case that Rock Pit and Central Pit can send grayel by rail to Acme for $1 per ton. Once the grave] is relocated, it can be trucked to the jobs. Reformulate this problem to determine hotsr shipping by rail could reduce the transportation costs for the gravel