This question is about the economic concept of elasticity. Consider two goods, Good-A and Good-B. All else equal, a decrease in the price of Good-A from $42 to $38 results in a decrease in the quantity demanded of Good-B from 120 units per day to 40 units per day.

A) Identify and calculate the relevant elasticity (i.e. the one that can be calculated from the information above). BE SURE TO SHOW YOUR WORK, YOU WILL GET PART MARKS FOR PROPER FORMULAS ETC.

B) Provide an explanation for the value you calculated in Part A (i.e. what does it tell you?). Explain all that you can. NOTE: if you didn't complete Part A, make up a number and provide an explanation.