There are many numbers between 500 and 1000 divisible by 3 and 9. Any number divisible by 9 is divisible by 3. How about 900?
There are 232 numbers between 1 and 500 that are divisible by 3 or 5.
400 of them.
456
Eight of them.
453
How about 450
420, 450, 480
450 is one of 3 possible answers.
There are many numbers between 500 and 1000 divisible by 3 and 9. Any number divisible by 9 is divisible by 3. How about 900?
To get a number like this, it CANNOT be even. The number 453 is divisible by 3(goes into 453 ninenty one times), but not by 2.
There are 232 numbers between 1 and 500 that are divisible by 3 or 5.
400 of them.
400
To find out if a number is divisible by 3 add up all it's digest and check if the total is divisible by 3. to check if a number is divisible by 2 check if the last digit is divisible by 2. So one such number is 405.
There are (500-100)/2 = 200 numbers divisible by 2 between 100 and 500 counting 100 but not 500. Of these (500-100)/8 = 50 are divisible by 8. So there are 150 numbers between 100 and 500 divisible by two but not by 8. By relative primeness exactly 50 out of these 150 are divisible by 3 and therefore these 50 are exactly the ones divisible by 6 but not by 8.
A prime number is divisible only by 1 or itself.