WBCS Mains 2021 (Held On May 2022) Official Paper-V

Consider the following statements regarding GST (Goods and Services Tax):
(i) Both Central and State taxes will be collected at the time of sale.
(ii) Central and State GST will be charged on manufacturing costs.
Which of the statements given above is/are correct?

Where are the words 'Unity and Integrity of the Nation' found in the Indian Constitution?

The concept of 'Directive Principles of State Policy' (DPSP) was borrowed from:

The concept of 'Single Citizenship' in India was borrowed from which country?

In which year were the words "Socialist" and "Secular" added to the Preamble of the Indian Constitution?