- A12
- B9
- C15
- D21
Step-by-Step Solution
3, 6, 9, 12, 15, 18, 21 — the middle term of an evenly spaced list is the average: 12.
Answer: A) 12
Don't just memorise the answer — build a daily practice habit.
Practice 5 Similar Questions Free →All Averages & Ages practice questions