Correct Answer & Explanation
Option A
• The sequence contains two intertwined sub-series:
Even-positioned terms: 2, 4, 8, 10 (differences are +2, +4, +2...)
Odd-positioned terms: 1, 2, 3, 7, ?
1 + 1 = 2
2 + 1 = 3
3 + 4 = 7
7 + 4 = 11
• Hence, the missing term is 11.