Question

how various activities have been classified into sectors

Answer 1

Under category of 1.Primary sector 2.Secondry sectors 3.teritiary sector

Answer 2

Activities has been classified into sectors in the following ways—

ON BASIS OF KIND OF ACTIVITIES
1) Primary
2) Secondary
3) Tertiary

ON THE BASIS OF WAY PEOPLE ARE EMPLOYED
1) Organized
2) Unorganized

ON BASIS OF OWNERSHIP
1) Public
2) Private