60 numbers
8100
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.
45 multiples of 2 plus 30 multiples of 3 minus 15 multiples of 6 equals 60 numbers
There are many multiples of five. Some are: 5, 10, 15, 20, 25, 30. If you want more, then just keep counting up by five.
60 numbers
There are 450 of them.
8100
81
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.
4500 of them.
There are 6,750 such numbers.
There are 9*10*9 = 810 such numbers.
45 multiples of 2 plus 30 multiples of 3 minus 15 multiples of 6 equals 60 numbers
There are 898 three-digit even numbers. Nine of them are multiples of 55. That leaves 889 * * * * * There are 450 three-digit even numbers and 17 of them are multiples of 55. So that leaves 433.
There are 720 of them. The three digit counting numbers are 100-999. All multiples of 5 have their last digit as 0 or 5. There are 9 possible numbers {1-9} for the first digit, There are 10 possible numbers {0-9} for each of the first digits, There are 8 possible numbers {1-4, 6-9} for each of the first two digits, Making 9 x 10 x 8 = 720 possible 3 digit counting numbers not multiples of 5.
I believe there are 81. There are 9 after every multiple of 10, including 90.