INDIA'S tour of the West Indies is on and all I can think of at the moment is centuries. Sachin has equalled the record of Sir Donald Bradman, but we are still 29 centuries or so behind Manava, in terms of our ability to do mathematics. Most of us still can't do what he could do 29 centuries ago, whereas, mathematical wizardry is a myth; the more you learn, the more demystified the subject looks… it's much like cricket… comes with practice.

'The Manava Sulbasutra' is not the oldest; the one by Baudhayana is older and there are at least three other Sulbasutras that are more significant. Manava, Vedic priest, also gave an approximate value of pi that was 25/8=3.125.

A man called Spike Lee once said: "Power is knowing your past." Many of you want to know more about Manava and his works. Perhaps, the Archaeological Survey of India can help you in restoring the leaves and decoding the script.

Remember the city surrounded by a circular wall… blue house… yellow house, where Manava was asked to find out the radius of the circle formed by the wall and he remained silent? Though Manava and the priest used the knowledge of geometry and not trigonometry to solve the puzzle, the best solution that I received was: "Let a be the angle between the line from the yellow house to the north gate and the line from the yellow house to the blue house. sin(a)=r/(r+3); tan(a)=9(2r+3); cos(a)=sqr(1-sin2(a)) =sqr(1-sin2(r/(r+3))) =sqr(6r+9)/(r+3); tan(a)=sin(a)/cos(a)=(r/(r+3))*((r+3)/sqr(3*(2r+3))) =r/sqr(3*(2r+3)); equating the two expressions for tan(a), we get: 9*sqr(3)*sqr(2r+3) =r*(2r+3); 9*sqr(3)=r*sqr(2r+3); 243=r2*(2r+3); 2r3+3r2-243=0 factorised to: (2r-9)*(f2+6r+27)=0; r=4.5.

There are five who have sent in the correct solution — Rohit Pardasani of Class X-C of Bhavan Vidyalaya, Chandigarh (He says that the radius can also be 18.5 miles; how, he does not say), Vrinda Prasad Tiwary of Siksha Deep Public School of Panipat, Charanpal Singh, Ranjeet and Rajeev Kumar Tak.

The second part of the puzzle was: Why did Manava remain silent? — Rohit says because there is no definite solution; Vrinda says because he did not want to defeat the teacher; Ranjeet says because he realised the flaw in his theory — if he had used triangles in place of rectangles and squares, there would have been no error due to approximation; Charanpal does not say anything and Rajeev does not know. If I were to choose an answer from the readers (which is indeed the case), I would choose Vrinda's because it is nearer to the truth, though rather evident. Manava remains silent to save the priest after he suddenly realises the joy of being interested in mathematics for its own sake and not using it only for religious purposes. The priest won because, by making him play this mind game, he was able to activate Manava's rational mind. We don't learn about many great mathematicians of the world in school or college, but never mind; you will always find them in Mind Games. Keep writing at The Tribune or adityarishi99@yahoo.co.in.