Sum of Positive Integers Less Than 150 Not Multiples of 5 or 7

[Michael_Light]

Homework Statement

Find the sum of the positive integers which are less than 150 and are not multiples of 5 or 7.

Homework Equations

The Attempt at a Solution

I tried it... Can anyone give me some hints or tips...?

 

[eumyang]

Find:
A) The sum of the positive integers from 1 to 149,
B) The sum of the multiples of 5 from 5 to 145,
C) The sum of the multiples of 7 from 7 to 147,
D) The sum of the multiples of 35 from 35 to 140.

Then, your final answer will be A - B - C + D. (We have to add the answer in D because by subtracting the answers in B and C, we are removing the multiples of 35 twice.)