There are 450 even three-digit integers, from 100 to 998.
This excludes numbers with leading zeroes (000 to 099).
100
None. 3 digit numbers are not divisible by 19 digit numbers.
998
More than one
For the first digit there would be 4 options For the second digit there would be 3 options for the third digit there would be 2 options Thus 4*3*2 = 24 three digit numbers can be formed if each digit can only be used once in a 3 digit number made.
100
999 What is even odd? 3 digit odd numbers 101,103,105...999 so count them = 450 3 digit even numbers 100,102,104...998 so count them = 450
Zero.
Yes. By 1 digit, 2 digit and some even by other 3 digit numbers.
None. 3 digit numbers are not divisible by 19 digit numbers.
998
There are 151 3-digit numbers that are divisible by 6.
More than one
The 3-digit counting numbers are 100 through 999 = 900 numbers.Half them are multiples of 2 (even numbers).The other half are not . . . 450 of them.
24 of them. So we have a 2 or 6 in the unit position, therefore (2)(4)(3) = 24 even three-digit numbers, can be formed.
There are 84 such numbers.
The final digit must be a 2 to form an even number. The first digit may be any of three remaining digits (1, 3, 5) while the second digit may be any of the two remaining digits. All together, that makes 3*2 = 6 distinct even numbers.