100 integers from 500 - 599 contain at least one 5
And in each of the 499 integers
_5, _15, _25, _35, _ 45, _55 , _65, _ 75, _ 85 , _ 95
In each hundred from 1 to 499 contain at least one 5
And there are 5 sets of these = 5 * 10 = 50
And in each hundred from 1 to 499 we have the integers
_5_ where the last digit is not a 5
And we have 9 of these in every hundred
So...we have 5 * 9 = 45 of these
So....100 + 50 + 45 = 195
Just as Dimitristhym found !!!
