158490

The numbers under 10 have a single digit, so when you write it down it counts as writing 1 digit. Numbers starting from 10 has two digits, so it counts as writing 2 digits.
from 1~9 it is 1X9=9 she wrote 9 digits
she wrote a total of 17 digits so 17-9=8
she has 8 digits left, and from
10~20 each number counts as writing 2 digits
8/2=4, so she wrote 4 two-digit numbers which is 14

first answer 14

If she writes the number up till 20,
1~9 = 9 digits
10~20= 2 X 11=22 digits
22+9=31
total 31 digits

Answer: 31