Consider the following former Presidents of India: 1. Dr. Sarvepalli Radhakrishnan 2. Dr. Zakir Hussain 3. Neelam Sanjiva Reddy How many of the above Presidents has/have 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). Dr. Zakir Hussain served as Vice-President (1962-1967) before becoming President (1967-1969). Neelam Sanjiva Reddy, however, never served as Vice-President — he became President directly in 1977 after serving as Lok Sabha Speaker. Hence, 2 of the listed former Presidents also served as Vice-President.