When supply increased by 9 billion bushels per year and demand was D2, the equilibrium quantity increased by less than 9 billion bushels per year.

When supply increased by 9 billion bushels per year and demand was D2, the equilibrium quantity increased by less than 9 billion bushels per year. Demand wasn’t elastic enough for the equilibrium quantity to increase by 9 billion bushels per year. How elastic would it have to be for the equilibrium quantity to increase by 9 billion bushels per year?