A series is given with one term wrong. Select that wrong term from the given…
2021
A series is given with one term wrong. Select that wrong term from the given alternatives. AKTU, BIUS, CGVQ, DEWN, ECXM
- A.
DEWN
- B.
BIUS
- C.
ECXM
- D.
CGVQ
Attempted by 24 students.
Show answer & explanation
Correct answer: A
Concept
In a letter-group series, each character position forms its OWN independent alphabetical sequence. To find the wrong group, analyse each position across all groups separately and check whether it follows a single, constant step (the gap between consecutive letters, counting A=1, B=2, ... , Z=26).
Application
Write the groups one below another and read each column down:
Group | Pos 1 | Pos 2 | Pos 3 | Pos 4 |
|---|---|---|---|---|
AKTU | A (1) | K (11) | T (20) | U (21) |
BIUS | B (2) | I (9) | U (21) | S (19) |
CGVQ | C (3) | G (7) | V (22) | Q (17) |
DEWN | D (4) | E (5) | W (23) | N (14) |
ECXM | E (5) | C (3) | X (24) | M (13) |
Now read the per-position step:
Position 1: A, B, C, D, E increases by +1 each time — consistent.
Position 2: K, I, G, E, C decreases by -2 each time (11, 9, 7, 5, 3) — consistent.
Position 3: T, U, V, W, X increases by +1 each time (20, 21, 22, 23, 24) — consistent.
Position 4: U, S, Q, ?, M should decrease by -2 each time (21, 19, 17, 15, 13), so the fourth value must be 15 = O. The group spelling DEWN has N (14) in this position instead of O (15).
So the fourth position breaks the -2 rule only at the group spelled DEWN; making it DEWO would restore the pattern. DEWN is therefore the wrong term.
Cross-check
Confirm the corrected group DEWO against every column: D (4, +1 from C), E (5, -2 from G), W (23, +1 from V), O (15, -2 from Q). All four positions then follow their own rule, which verifies that only the last letter was off.