Answer:
C. ⅓ × (8 + 7) + 12
Explanation:
Let's translate each statement given to numerals and symbols first:
Twelve => 12
One-third => ⅓
Sum of 8 and 7 => (8 + 7)
Representing this statement altogether will be:
⅓ of (8 + 7) = ⅓ × (8 + 7)
If 13 is added, we would get:
⅓ × (8 + 7) + 12