Letter series Z X U Q – UGC NET Question

The positions of the letters are Z(26), X(24), U(21) and Q(17). The decreases between them are −2, −3 and −4, which form an increasing sequence of negative steps in magnitude. The next step should be −5, giving 17 − 5 = 12, which is the letter L. Hence L uniquely satisfies the pattern of successively larger backward jumps.

Option A:
Option A, O, lies at position 15, which would give a decrease of only 2 from Q. This contradicts the trend of increasing the size of the backward step. Since the differences must grow by 1 each time, O cannot fit the rule.

Option B:
Option B, N, is at position 14, implying a decrease of 3 from 17. This repeats a previous step size instead of extending it to −5. Therefore N does not reflect the evolving pattern of differences.

Option C:
Option C, K, corresponds to position 11, giving a drop of 6 from Q. This overextends the next decrement beyond what the sequence suggests. Because the model clearly shows steps of −2, −3, −4, then −5, moving to −6 breaks the logic.

Option D:
Option D is correct because L, at position 12, produces the required decrease of 5 from 17. It aligns with the systematic growth of the backward interval. By respecting the exact structure of the differences, L is the only consistent next term.