Questions

The study of statistics such as births, deaths, income, or the incidence of disease, which illustrate the changing structure of human populations.

In brief, Study of both quantitative and qualitative aspects of human population.

1. Quantitative aspects include composition, density, distribution, growth, movement, size, and structure of the population.

2. Qualitative aspects are the sociological factors such as education quality, crime, diet, development, nutrition, wealth and well being.

According to the Mercer’s 19th annual Quality of Living survey released Hyderabad emerged as the best city in terms of living standards among Indian cities for the third year in a row.

The logic in this puzzle is summing the result of [subtraction of upper two digits] & [addition of lower two digits] 

Hence, the result is  

(5 - 3) + (2 + 8) = 2 + 10 = 12.