What iz d. sum ov all 3digit positive integers exist dat when divided by 7 leave a remainder ov 5

15x7=105

105+5=110
So, 110 is the first
then the next is 117 then 124.
sum=7 (15+16+17+....to end)+5(end-14)
What is end?
end occurs at 995÷7 or 142
sum=7 (15+16+17+...+142)+5 (128)
Now the first () is an arithmetic series for whicih there is a standard formula you can look up. Then you have it.