South America in Upfront magazine: the top 5 nations

Leover and Bernadette's South American Travel Map
Originally uploaded by leover

In Upfront magazine's world review (Nov 9), see South America, p. 35.

a) Devise and explain your way of ranking the most effective nations of S Amer. Use at least 3 criteria.
b) Using your formula, rank the the 5 nations displaying the Highest Quality of Life.