Series Set

Q : In the given sequence N, L, J, H, ?, which letter should replace the question mark ?


Option : (A) F  (B) B (C) G (D) E


Ans: (D) F


Explanation: Convert letters to their alphabet positions: N=14, L=12, J=10, H=8. The pattern decreases by 2 each time (14 → 12 → 10 → 8 → 6). Position 6 corresponds to F.


Q. Z, V, R, ?, J, F Option : (A) N (B) M (C) K (D) P


Ans: (A) N


Explanation: Letter positions: Z=26, V=22, R=18, N=14, J=10, F=6 — each step decreases by 4. So after R (18) the next is N (14).


Q. XQ, UN, RK, OH, LE, ? Option : (A) GA (B) JC (C) HA (D) IB


Explanation:
First letters: X-24, U-21, R-18, O-15, L-12 → decrease by 3.
Second letters: Q-17, N-14, K-11, H-8, E-5 → also decrease by 3.
Next: 12-3=9 → I, 5-3=2 → B = IB.


Q.  Find the next pair in the series: ap, ds, gv, ?


Options: (A) mq  (B) st  (C) lr  (D) jy


Answer: (D) jy


Explanation: First letters: a(1), d(4), g(7) → +3 each. Second letters: p(16), s(19), v(22) → +3 each. Next pair: j(10) and y(25) → jy


Q. A, B, D, G, K, P, ?


Options: (A) V  (B) X  (C) Z  (D) W


Explanation:
Position of letters → A(1), B(2), D(4), G(7), K(11), P(16).
The difference between positions increases by +1 each time:+1, +2, +3, +4, +5 → next will be +6.
So, 16 + 6 = 22, which corresponds to V.


 Q. J L K M O N P R Q S ? ? Options: (A) TU (B) RS (C) UT (D) UV


J L K M O N P R Q S ? ? (UT)


Split into odd and even positions


Odd positions (1, 3, 5, …): J, K, O, P, Q


Even positions (2, 4, 6, …): L, M, N, R, S


Quick trick summary:


Split odd & even positions.


Look for small jumps (+1, +2, +3, …) in each.


Predict next letter separately.


Merge to get the final answer.


Q. Sequence: AC, CF, EJ, GO, ? Options: (A) JV (B) IV (C) IU (D) JU


Split letters:


First letters: A, C, E, G → +2 each → Next = I


Second letters: C, F, J, O → +3, +4, +5 → Next = U


Combine: I + U = IU


Answer: IU


Simple trick:


Split pairs into first and second letters.


Track incremental jumps separately.


Merge results.


 Q. LS, QY, VE , ? Options: (A) VK (B) AJ (C) BJ (D) AK


Simple Trick for LS, QY, VE, ? → AK:


Split the pair into first and second letters:


First letters: L, Q, V


Second letters: S, Y, E


Convert to numbers (A=1, B=2… Z=26):


L=12, Q=17, V=22 → pattern: +5 each step


S=19, Y=25, E=5 → pattern: +6 each step (wrap after 26)


Apply the pattern to get the next letters:


First letter: V + 5 → 22+5=27 → wrap → 1 = A


Second letter: E + 6 → 5+6=11 → K


Combine → AK


Rule:


Split pairs, convert to numbers, find jumps, apply, wrap around Z, then combine.


Q. Series: ST, TU, UV, VW, ? Option : (A) WY B. WX (C) wz (D) WV


Split into two letters each time


First letters: S, T, U, V - pattern +1 each time


Second letters: T, U, V, W - pattern +1 each time


Next letters


First letter: V - W


Second letter: W - X


So, the next term is WX


Answer: (B) WX


Q. 5040, 840, 168, 42, 14, ? Option : A. 7 B. 2 C. 6, D.5 


Soln,


Find the pattern,


Let's divide each term by the next one:


5040 ÷ 840 = 6,


840 ÷ 168 = 5,


168 ÷ 42 = 4,


42 ÷ 14 = 3,


So the pattern is dividing by decreasing numbers: 6, 5, 4, 3...


Continue the pattern,


Next divisor should be 2 (since the pattern decreases by 1 each time).


So,


14 ÷ 2 = 7


Ans: 7


Q. 117, 118, 120, 129, 193, ? Option : A. 210 , B. 420, C. 818, D. 618 

Soln,


Differences:


118−117 = 1 (= 11),


120−118 = 2 (= 21),


129−120 = 9 (= 32),


193−129 = 64 (= 43),


Next difference = 54 = 625.,


So next term = 193+625=818.,


Ans: 818 (Option C)


Q)  2, 3, 7,16, 32, 57, ? Option: A. 93, B. 107, C. 92, D. 100 



Soln,


Find differences,


3 − 2 = 1, 7 − 3 = 4, 16 − 7 = 9, 32 − 16 = 16, 57 − 32 = 25,


Differences = 1, 4, 9, 16, 25 → these are 1², 2², 3², 4², 5²,


Next difference,


Next should be 6² = 36,


Add to last term: 57 + 36 = 93


Ans: 93 (Option A)


Q)   6, 7, 11, 20, 36, ? Option A. 60, B. 57, C. 61, D. 51 


Soln,


Find differences,


7 − 6 = 1 ,


11 − 7 = 4 ,


20 − 11 = 9 ,


36 − 20 = 16 ,


Differences = 1, 4, 9, 16 → these are 1², 2², 3², 4² ,


Next difference = 5² = 25,


Add to last term,


36 + 25 = 61


Ans: 61 (Option C)


Q) Find known differences: 848, 969, ? , 1282, 1478 Option. A. 1000, B. 1113 C. 1013, D. 999 


969 − 848 = 121,


1282 − ? = (unknown) ,


1478 − 1282 = 196 , 


We notice 121 = 11², 196 = 14² → appears like square numbers increasing by 3 in the base (11, 14...).


Continue the pattern , Base numbers: 11, 12, 13, 14 → squares: 121, 144, 169, 196 ,


So the differences should be: +121, +144, +169, +196 ,


Fill in missing term,


848 + 121 = 969,


969 + 144 = 1113,


1113 + 169 = 1282,


1282 + 196 = 1478,


Answer: 1113 (Option B)


Q) 1, 4, 9, 16, 25, ? Option. A. 31, B. 36, C. 8, D. 40 


Soln.


1, 4, 9, 16, 25 = 1², 2², 3², 4², 5²


Next = 6² = 36


Ans: 36 (Option B)


Q) 32, 57, 93, 142, 206, ? Option. A. 213, B. 26, C. 216, D. 287 

Soln.


Find differences,


57 − 32 = 25,


93 − 57 = 36,


142 − 93 = 49,


206 − 142 = 64,


Differences = 25, 36, 49, 64 → these are 5², 6², 7², 8²,


Next difference,


Next = 9² = 81,


Add to last term,


206 + 81 = 287


Ans: 287 (Option D)


Q. Given series:
1, 1, 2, 8, 3, 27, 4, ?, 5, 125 Option : (A) 32  (B) 96  (C) 36  (5) 64


Observe pattern



  • Odd positions (1st, 3rd, 5th, 7th, 9th, …) → 1, 2, 3, 4, 5 → increase by +1 each time

  • Even positions (2nd, 4th, 6th, 8th, 10th, …) → 1, 8, 27, 64, 125 → that’s 1³, 2³, 3³, 4³, 5³
    Term at position 8 (even) = 43=64


Q. Find the next number in the series: 87, 88, 80, 107, 43, ? Option : (A) 126  (B) 70  (C) 98  (D) 168


Answer: (D) 168


Reason: Differences are +1, −8, +27, −64 which are +1^3, −2^3, +3^3, −4^3 


Next difference = +5^3 = +125. So, 43+125=168..


Q. 1, 1, 2, 8, 3, 27, 4, 7, 5, 125. Option : (A) 32  (B) 96  (C) 36  (D) 64


(A) 32


(B) 96


(C) 36


(5) 64


Given series: 1, 1, 2, 8, 3, 27, 4, ?, 5, 125


Pattern



  • Odd positions (1st, 3rd, 5th, 7th, 9th, …) → 1, 2, 3, 4, 5 → increase by +1 each time

  • Even positions (2nd, 4th, 6th, 8th, 10th, …) → 1, 8, 27, 64, 125 → that’s 1³, 2³, 3³, 4³, 5³
    Term at position 8 (even) = 43=64


Answer: (D) 64


Q: Find the next number in the series: 87, 88, 80, 107, 43, ? Options: (A) 126  (B) 70  (C) 98  (D) 168


Soln:
Look at the pattern carefully - each step alternates between adding and subtracting cubes of consecutive natural numbers:


+1^3,−2^3,+3^3,−4^3,+5^3


Now calculate step by step:



  •       87+1^3 = 87+1 = 88

  • 88−2^3=88−8=80

  • 80+3^3=80+27=107

  • 107−4^3=107−64=43

  • 43+5^3=43+125=168


Ans: 168