If the first half of the following series is reversed, then which item is 7th to the right of the 12th item from the right side? The series is:
Z + S 1 K J 7 P H M 3 A X 6 Q I G E F O
Midpoint is 10. We have to find 20 - 12 + 7 = 15 + 1th item from the left side. Since the location lies in the right half, reversing the series has no effect in this zone. So counting from the left side, the item is I.