in and ap 1,2,3,4,5,6,7,8,9
11,12,13,14,15,16,17,18,19 and like that nonzzero digit find tn
Solution) First break the ''n'' number in terms of 10''s power. For e.g if n=3259 write it as 3X10^3+2X10^2+5X10+9. Then replace 10s by 9. 3X9^3+2X9^2+5X9+9. It will be the answer. 2403 is the answer in this example.
Actually since there is no 0 in the series, its in the number system with base 9. So we are just converting from base 9 to base 10.