How is a population structured?

The following graphs represent age pyramids of a population. Identify the correct sequence for $A$, $B$, and $C$.

At one time,the number of cheetahs in a habitat is $80$. Their birth rate is $4$ and death rate is $2$. Among them,$6$ cheetahs are internal migrants (immigration) and $3$ cheetahs are migratory (emigration). Calculate the population density of cheetahs in that habitat.

Differentiate between Immigration and Emigration.

The tiger census in our national parks is often based on . . . . . . .

In the given figure,which factors are responsible for the increase in population density?