Concept:Three statements about medieval South Indian science are to be verified for correctness.
Explanation:Statement 1 is correct.
The Katapayadi system associates each Sanskrit consonant with a digit.
It was invented by Vararuchi of Kerala, who authored the Chandra Vakyas.
This system was used to compute the Moon's position on any day of the year.
Statement 2 is correct.
Achyuta Pisharati (1550–1621) was a scholar from the Kerala school of astronomy.
He wrote
Uparagakriyakrama, a treatise that explains lunar and solar eclipses.
Statement 3 is correct.
Ravi Varma of Mahodayapuram established an astronomical observatory.
He is also credited with inaugurating the Kollam era, a regional calendar system.
All three statements factually describe contributions of medieval South Indian science.
Answer:1, 2 and 3