Try this:
Program
using System;
class InventoryManagement
{
public static void Main()
{
float dr,sc,cpu;
//dr = Demand rate, sc = setup costs, cpu = cost per unit
double EOQ,TBO;
// EOQ = Economic Order Quaitity
// TBQ = Optimal Time Between orders
Console.WriteLine("\t\t***** Inventory Management System *****");
Console.WriteLine(""); // Blank Line
Console.Write("Enter the Demand Rate : ");
dr = float.Parse(Console.ReadLine());
Console.Write("Enter the Setup Costs : ");
sc = float.Parse(Console.ReadLine());
Console.Write("Enter the Cost Per Unit : ");
cpu = float.Parse(Console.ReadLine());
Console.WriteLine(""); // Blank Line
EOQ = Math.Sqrt(2*dr*sc/cpu); // Calculating EOQ
TBO = Math.Sqrt(2*sc/(dr*cpu)); // Calculating TBO
Console.WriteLine("Economic Order Quaitity = " +EOQ);
Console.WriteLine("Optimal Time Between orders = " +TBO);
Console.ReadLine();
}
}