1. The Hardrock Concrete Company has plants in three locations and is currently working on three major construction projects, each located at a different site. The shipping cost per truckload of concrete, daily plant capacities, and daily project requirements are provided in the table below. Formulate this as a linear program to determine the least-cost way to meet the requirements. Find the optimal solution using LINDO/AMPL. Hint: Define Xij as the number of truckloads to send from plant i to project j. A set of constraints consists of not exceeding the capacity and another set of constraints consists of satisfying the demand.

2.  

From/To Plant 1 Plant 2 Plant 3 Requirements (truckloads) Project A $100 $120 $90 40 Project B $40 $50 $70 50 Project C $110 $80 $60 60 Capacity (truckloads) 70 50 30 150*