The price elasticity of demand for coke is -0.24. The price elasticity of supply for coke is 0.38. The income elasticity of demand for coke is 0.8. The equilibrium quantity is 39.95 metric tons, equilibrium price is $ 207 per metric ton and the average household income is $ 58,000.

a) Find the demand equation for Coke

b) If a recession causes average household income to fall to $ 51,000, what will the resulting change in quantity for coke be?