CAT Questions

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The only gem of world made of a single element is Diamond.

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.

Here the given expression, 

X2 + X2 is an algebraic expression. Here in this expression the terms are like terms. Now to add them, add their coefficients.

Here in the given expression, the like terms are two X2

Hence, adding their coefficients i.e, 1 + 1 = 2

Therefore, 

X2 + X2 = 2X2.

Secondary pollutants include ozone, which is formed when hydrocarbons (HC) and nitrogen oxides (NOx) combine in the presence of sunlight.

Whereas Primary pollutant are those pollutants that are directly emitted from their sources, like CO2, CO, SO2 as these gases are directly emitted form burning of fossil fuels.

Acid rain, which is formed when sulfur dioxide or nitrogen oxides react with water, sulfuric acid etc.

Hence, Acidrain is a secondary air pollutant.