1. The problem asks to find the value of $\sum (x+1)$ for the values $x = 2, 4, 6$. 2. The summation formula here means we add each $x+1$ for each value of $x$. 3. Calculate each term: $2 + 1 = 3$ $4 + 1 = 5$ $6 + 1 = 7$ 4. Now sum these results: $$3 + 5 + 7 = 15$$ 5. Therefore, $\sum (x+1) = 15$ for $x = 2, 4, 6$. This matches the option 15.