The sequence 7 M % K 4 B @ P 2 W & 9 T F # 5 J R $ 6 D N 8 is written out afresh with its twenty-three elements in reverse order. In the new sequence, which element stands ninth from the left end?

The ninth element from the left of the reversed sequence is the ninth from the right of the original, which is element number 23 − 9 + 1 = 15. Counting to fifteen in the original gives #. F sits at place 14 and 5 at place 16, so either is what a slip of one in the reversal count returns. The element ninth from the left of the original, without reversing at all, is 2.