Letter series A C F J O – UGC NET Question

The positions of the letters are A(1), C(3), F(6), J(10) and O(15). The successive differences are +2, +3, +4 and +5, forming an increasing sequence of natural numbers. The next difference should be +6, so the next position is 15 + 6 = 21, which corresponds to U. Therefore U is the only letter that continues the pattern of steadily increasing gaps.

Option A:
Option A, T, lies at position 20, giving a difference of 5 from O. This simply repeats the last increment instead of increasing it to 6. Since the series clearly shows the gaps growing by 1 each time, T does not meet the rule.

Option B:
Option B, U, is correct because its position 21 equals 15 + 6, matching the expected next difference. It maintains the idea that each step forward in the series uses a gap one larger than before. This adherence to the underlying numerical pattern makes U the valid continuation.

Option C:
Option C, V, at position 22, would correspond to a +7 jump from O. That goes beyond the required next difference of +6 and distorts the incremental pattern. As a result, V cannot be accepted as the next term in the series.

Option D:
Option D, W, at position 23, deviates even more from the predicted increment by adding 8. This breaks the smooth progression of 2, 3, 4, 5, 6 in the differences. Hence W is not consistent with the logic of the sequence.