Consider the following former Presidents of India : 1. Dr. Sarvepalli Radhakrishnan 2. Dr. Zakir Husain 3. Neelam Sanjiva Reddy How many of the above also served as Vice President of India ?

Dr. Sarvepalli Radhakrishnan served as the first Vice President of India (1952-1962) before becoming President (1962-1967) — yes. Dr. Zakir Husain served as Vice President (1962-1967) before becoming President (1967-1969) — yes. Neelam Sanjiva Reddy, however, never served as Vice President; he was a Speaker of the Lok Sabha and was elected directly as President in 1977 unopposed. Hence only TWO of the three listed Presidents had previously served as Vice President.