This document is proposing an inventory system that is two-echelon for a supply chain that is coordinated and non-coordinated with one retailer and manufacturer. The retailer experiences the demand that is dependent on quadratic price and assumed to be price driven. Profit is completely dependent on the effectiveness of supply chain. Profit is the difference between the gross revenue and the total cost, whereas total cost includes carrying cost, transportation cost along with the cost of annual ordering. For a coordinated and non-coordinated supply chain, a mathematical model is being introduced. The primary objective of the mathematical model is to show the effective ordering quantity of the retailer, effective lot size of the producer, and the optimal quantity of the transportation from manufacturer to the retailer. The impact of the model parameters on objective function and variables is demonstrated with the help of a sensitivity analysis.