John an apprentice, engineer and amateur trumpet player, was earning ₦30 per week before accepting Full-time employment in a top orchestra, for which he now receives ₦150 per week. ₦120 of his current weekly earnings can be described as________

Effective demand for a commodity is desire for that commodity backed by_______

A commodity is defined as normal when its demand changes in the same direction as______

Which of the following matters may account for changes in demand?
 

I - changes in consumer preferences
II - changes in real income
III - changes in distribution of incomes
IV - changes in levels of taxation

An example of a market which approaches fairly near to perfection is____________