Solution:

During his term as the Chief Justice of India, the then-President of India, Zakir Husain died suddenly, in harness, on 3 May 1969. Then Vice President of India Mr. V. V. Giri became the acting President. Later, Giri resigned from both offices as acting President and Vice-President to become a candidate in the 1969 Presidential Election. Hidayatullah then served as the President of India for a short period from 20 July to 24 August. The visit of President of the United States Richard Nixon to India made his Presidential term historic.

After his retirement, Hidayatullah was elected as the Vice-President of India by a consensus among different parties and occupied that high office with distinction from 1979 to August 1984. During his tenure as the Vice-President, he won the respect of all concerned for his impartiality and independence.

In 1982, when the then President Zail Singh went to the U.S. for medical treatment, Vice-President Hidayatullah officiated as President from 6 October 1982 to 31 October 1982. Thus, he officiated as acting President twice.

Having served at all of these positions made Hidayatullah unique among other members of Indian history. He became the only person to have served in all three offices of Chief Justice of India, President of India, and the Vice President of India.