President A P J Abdul Kalam Wednesday appeared stumped when a student of an Indian international school in Singapore asked him why he has not got married.

"Sir, why have you not found a life partner?" the student asked after the President delivered an extempore lecture in which he restated his vision of a peaceful and prosperous world and the role of youth in the efforts to that end.

After a brief silence, the President replied "I wish all of you find the best life partner," drawing peals of laughter from the audience at the auditorium of the Bharatiya Vidhya Bhavan International School.

Replying to a question from a student on why he chose to become the President of India, Kalam said, "I felt I can market a developed India and transform India using science and technology."

The President also administered a five-point pledge to 200-odd students, urging them to have the courage to think differently, invent and make scientific discoveries.

Kalam, who wowed the youth in Singapore with his power-point presentations often punctuated with witty remarks, gave the pledge after his lecture.

The President's prescription to the students was to have courage to think differently, to invent, to discover, to compare the problems and succeed as also to work with courage for scientific discoveries. When one student asked Kalam how he derived so much confidence, he said confidence has to be inspired in youths by their parents and teachers who should never be pessimistic.

Recalling his association with his mentor and leading space scientist Vikram Sarabhai, Kalam said parents or teachers should not rebuke youth when they fail but goad them on to achieve success. Kalam started the session by recalling an anecdote in the life of Mahatma Gandhi whose mother had advised him that if he in his entire life can save the life of one person or better the life of somebody, "your worth as a human being is proved and life is a success."

The President recalled how legendary Tamil poet Thiruvalluvar had in his epic Thirukkural spoken about the need to speak the truth and honest actions.