Question: how many integers from 1 to 100 are divisible by 3 but not by 8?
Answer: 3 x 33 = 99 , the largest common multiple below 100. Hence, 33 integers divisible by 3. 3 x 8 = 24 so, multiples of 24, (24, 48, 72, 96) 4 of them are divisible by 8. So, my answer is 29 are divisible by 3 and not 8.