Four of them.
456
There are 22 numbers between 400 and 600 that are divisible by nine.
400 of them.
300.
The answer is 400-100-1 = 299 (excluding both 100 and 400).
50
500
59
The sum of the number of digits in all the numbers between 31 and 400 inclusive is 1041.
If you write all of the counting numbers from 200 to 400,you will write the digit ' 5 ' forty times.
110
two: 370 and 371