Final answer:
The question involves calculating the price elasticity of demand between two specific points for each pair to determine if the demand is elastic, inelastic, or unit elastic.
Step-by-step explanation:
The student is asking to compute the price elasticity of demand (PED) between two sets of points, specifically between points C and D, and points H and I.
To calculate PED, we use the formula:
PED = (% change in quantity demanded) / (% change in price)
The calculation involves determining the percentage change in quantity demanded and the percentage change in price between the two points and then dividing the former by the latter.
The result classifies the demand as either elastic (PED > 1), inelastic (PED < 1), or unit elastic (PED = 1).