Question: how many numbers ranging from 1 to 100 are not multiples of 3 and not divisible by 7?
Answer: While the number should be divisible by 7, since we do not want these numbers to be multiple of 3, we have to get rid of numbers 21, 42, 63 and 84 i. e. 4 numbers out of 14 numbers. 14 - 4 = 10. Thus there are 10 numbers (between 1 and 100) that are divisible by 7 but not 3.