Question: how many numbers between 1 and 100 are divisible by 17?
Answer: The number off odd multiples of 3 between 1 and 100 will be 33/2 = 16 remainder 1. Since both 3 (the smallest multiple of 3) and 99 (the greatest multiple of 3) are both odd, this means that you have 17 odd numbers divisible by 3 between 1 and 100. So your number will be 100 - 50 - 17 = 33.