$1^{st}$, $2^{nd}$, $3^{rd}$ dose of $DPT$ is given by

$I$. $6 \;weeks$ after birth

$II$. $10 \;weeks$ after birth

$III$. $14 \;weeks$ after birth

$IV$. $24 \;weeks$ after birth

$V$. $29\; weeks$ after birth

In which one of the following the birth rate is high & death rate is normal

Presently, the world population doubles after every

Population density of India is

The concept that “Population tends to increase geometrically while food supply increases arithmetically'' was put forward by