Sociilogy is on top of all books, Education is below Sociology. Accountancy is below Education.
Economics is above Psychology and Psychology is above Hindi.
Economics is not in the middle. So, in the middle lies the seventh book i.e. English.
Thus, the sequence from top to bottom is :
Sociology, Education, Accountancy, English, Economics, Psychology, Hindi.
There are three books between Accountancy and hindi -- English, Economics, Psychology.