Consider the following statements regarding the Directives outside Part IV of the Constitution:

1. Article 335 directs the consideration of claims of Scheduled Castes (SCs) and Scheduled Tribes (STs) for services, while maintaining the efficiency of administration in Union and State services

2. Article 350A emphasizes that it is the duty of the Union to provide instruction in the mother tongue of linguistic minority groups at the primary stage of education.

3. Article 351 mandates that the Union shall promote the development of Hindi language so that it may serve as a medium of expression for all the elements of the composite culture of India.

How many of the above statements are correct?