l. a) b) c) d) Using the midpoint formula, calculate the following price elasticity of demand (1 mark} The number of gallbladder operation fell from T000 to 4000 per week after its price increased from $6,000 to $15,000? The price of a bus ticket rises from $2.?5 to $3.75 and the number of tickets sold falls from 10 000 to 8500. The price of Pepsi-Cola increases from 40 cents to 50 cents per bottle and the quantity demanded decreases from 100 bottles to 50 bottles. The price of an ice-cream rises from $1 to $2 per unit, leads to a decrease in the quantity demanded from 100 to 80 units. If the crossprice elasticity of demand for Products A and B is +3.6, and for Products (3 and D is 5.4, what can you conclude about how these pairs of products are related? (02 mark} . What conclusion can you generate from the result of the previous Mo parts in terms of the signs e, + or -) of different elasticities? Specifically, why are the signs of income and across elasticities so important but the signs of price elasticities are almost irrelevant (1 mark}