Find the missing term: AZPK, BYQJ, CXRI, ?
Find the missing term: AZPK, BYQJ, CXRI, ?
Track each letter position separately. 1st letters go forward: A, B, C, D. 2nd letters go backward: Z, Y, X, W. 3rd letters go forward: P, Q, R, S. 4th letters go backward: K, J, I, H. Putting these together gives D, W, S, H.
Re-check your working by substituting the answer back into the original question.