One-digit and two-digit numbers occupy 9 + 2*90 = 189 positions. The amount of the rest positions from 190-th till 2020-th is 2020 - 189 = 1831. The number of the three-digit numbers occupying these 1831 positions is= 610.33. It means that the positions from 190 till 2019 are occupied by the three-digit numbers 100, 101, 102, . . . , 100+610-1 = 709. Hence, the digit in 2020 position is "7", the first digit of the number 710. ANSWER