30 cents per pack. B) Now suppose the farmer is instead given 240 feet of fence (h = 240). Complete the following table. By how much would the length L of the optimally designed pen increase? C) vVhen the amount of fence is increased from 200 to 240 (6.F = 40), what is the change in the optimal length (6.L)? 2.9. This demand curve. B) What is the choke price? C) What is the price elasticity of demand at P = 50?