I am trying to find the sum of multiples b/w $2$ and $10$ end points non-inclusive using the following mechanism and I don't know why I am getting the wrong answer. (I selected this small range intentionally just to check the result)
First I find the no. of multiples b/w $2$ and $10$ using
No. of Multiples = $\frac{10-2}{2} - 1 = 3$ So there are three multiples of 2 b/w $2$ and $10$
Sum of Multiples now is = Multiple$(1+2+3)$=$2(6)=12$
But The answer is supposes to be $4+6+8 = 18$ Why am I getting the wrong answer.
Edit: I think the problem is with the formula:
Sum of Multiples now is = Multiple$(1+2+3)$=$2(6)=12$
I got this from here 3rd Comment after the question