Newton's first law states that, if a body is at rest or moving at a constant speed in a straight line, it will remain at rest or keep moving in a straight line at constant speed unless it is acted upon by a force. This postulate is known as the law of inertia.
As the term define demo = population or demography means study of population.... India's population was growing slowly till 1920s but as seen from afterwards the mortality rate curved down and increased in population, hence 1921 is marked as YEAR OF GREAT DIVIDE
You can get another course by:-
1.Enroll for new course
2.Other course category
4.From here you can find one more course on vedic maths( I had forgotten the name )
[This course is also from 'Target Study Academy']