Answer:
7
Explanation:
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 1831%2F3 = 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