In the following question, find the term which does not fit into the series:
1CV, 5FU, 9IT, 13LS, 17PQ
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 17PQ
Each term has three parts, a number and two letters, and each part follows its own rule (letters by their place in the alphabet: C = 3, V = 22):
Number: 1, 5, 9, 13, 17 — adds 4 each time
First letter: C (3), F (6), I (9), L (12) — moves 3 places forward, so the fifth must be O (15)
Second letter: V (22), U (21), T (20), S (19) — moves 1 place back, so the fifth must be R (18)
The fifth term should be 17OR; the given 17PQ breaks both letter rules, so 17PQ is the term that does not fit.
Tip: The positions 5, 10, 15, 20, 25 belong to E, J, O, T, Y (“EJOTY”); counting from the nearest of these gives any letter’s place quickly.