According to the $2001$ census,the Indian population was:

In India,the number of females per $1,000$ males had been constantly decreasing. In which of the following years did this number increase?

On which day did the world population reach the $5^{th}$ billion mark?

In India,the population growth:

What are the probable factors that contributed to the population explosion in India?

The study of human population statistically is known as