The absolute value of the price elasticity of demand is -3.5 based on the information shown in the question above. This problem can be solved using the elasticity formula which stated as Ed = ((Q1-Q0)/Q0)% / ((P1-P0)/P0)%. In this formula, Ed is the elasticity of demand, Q1 is the current quantity, Q0 is the previous quantity, P1 is the current price, and P0 is the previous price (Calculation: -3.5 = ((600-400)/400)% / ((1.5-1.75)/1.5)%).