Question

sum of all integers from 1 to 100 which are not multiples of 3 or 7

Answer 1

Your answer should be: Total sum-(sum of multiple of 3+ sum of multiple of 7− sum of multiple of 21)

Since 21 is LCM of 3 & 7

Answer 2

Here's your answer.....

If you are familiar with unions and intersections of sets , then it is not a difficult problem.

Your answer should be: Total sum-(sum of multiple of 3+ sum of multiple of 7− sum of multiple of 21)

Since 21 is LCM of 3 & 7