Consider this series: 8 B R 4 % W 6 F 2 D @ 9 J 7 K * 3 5 T. Since the series holds nineteen elements, its tenth element stands at the centre. How many letters stand to the left of that central element?

The central element is the D at place 10. To its left lie 8 B R 4 % W 6 F 2, and the letters there are B, R, W and F — 4 in all. Answering 3 is the count of letters on the other side of the centre (J, K and T), and 5 comes of counting the central D itself as one of them. Answering 2 means missing two of the four.