Series Reasoning

SERIES REASONING (All Common Questions)

There are different types of SERIES REASONING:

(1) Complete the series
(2) Find missing number of the series
(3) Find Wrong number of the series


To solve these kind of series problem we must examine them with the ideas
a. Consecutive even numbers
b. Consecutive odd numbers
c. Consecutive prime numbers
d. Square of numbers
e. Cubes of numbers
f. Square root of numbers
g. Omission of certain numbers of letter in any consecutive order
h. Addition/Subtraction/Multiplication/Division by some number (eg. A.P & G.P) or any ohter relation

Complete the given series.




BDF, CFI, DHL, ? (A) CJM (B) EIM (C) EJO (D) EMI The right option is C Explaination → The series letters skipping follow BDF = BD and DF are +2 letters skipping each CFI = CF and FI are +3 letters skipping each DHL = DH and HL are +4 letters skipping each EJO = EJ and JO are +5 letters skipping each Hence, Option [C] alone follows

FAG, GAF, HAI, IAH, ? (A) JAK (B) HAK (C) JAI (D) HAL The right option is A Explaination → The series letters skipping follow All the first letter of each words are +1 letter skipping Middle letters are same And the third letters follow the pattern (-1, +3, -1, +3) Hence, Option [A] alone follows

DILQTYBG? (A) H (B) I (C) J (D) P The right option is C Explaination → The series letters skipping follow the pattern (+5, +3, +5, +3, +5, +3, +5, +3, +5) Hence, Option [C] alone follows

BC FG JK ? RS VW (A) LM (B) OP (C) QR (D) NO The right option is D Explaination → The series is read by following the pattern BC (DE) FG (HI) JK (LM) NO (PQ) RS (TU) VW Hence, Option [D] alone follows (letters within braces are skipped letters)

BYA, CXB, ? EVD (A) DVE (B) DCW (C) DXB (D) DWC The right option is D Explaination → Here, the first two letters are opposite/reverse while the third letters are consecutive letters Hence, Option [D] alone follows

LXF, MTJ, NPN, OLR, ? (A) PHV (B) PIU (C) PKX (D) PJW The right option is A Explaination → Here, each third letter skipping is +4 Therefore, the required word's last/third letter must be ended with V Hence, the right option is [A]

YANWY, DFMBD, IKNGI, NPMLN, ?, XZMVX (A) RUMSR (B) SUNQS (C) UWNSU (D) VUMTV The right option is B Explaination → In the following series first ,second ,fourth and fiftieth letters are moved five steps forward and third letter N and M are reversed alternatively to form the next term. Hence following the series the next term is SUNQS

PEXKW, RFWMU, TGVOS, VHUQQ, XITSO, ? (A) ZJSUM (B) YJSUZ (C) ZKSVJ (D) JZSTN The right option is A Explaination → It is +2 letters skipping of each letters of a previous term to make the next term X+2→Z I+1→J T−1→S S+2→U O−2→M Hence the answer is ZJSUM.

AYBZC, DWEXF, GUHVI, JSKTL, ?, POQPR (A) MQDRN (B) QMONR (C) MQNRO (D) NQMOR The right option is C Explaination → It is letter skipping, so lets check with each first letters A+3→D, D+3→G, G+3→J, J+3→M, M+3→P Here the word in ? is starting with M So, possible answer is option (a) and (c) To Specified the right option we need to check them where they have unique letters, (say last letter) C+3→F, F+3→I, I+3→L, L+3→O, O+3→R Hence the answer is MQNRO.

ZYYZR, ABVUM, ?, BCUTL, XWABT, CDTSK (A) YXZAS (B) ZYABT (C) XWYZR (D) YXZAB The right option is A Explaination → It is letter skipping and is dual (two) serieses, so lets check Here, In 1st, 3rd and 5th, each first letters are consecutive from right to left, i.e. X, Y, Z So, the word in ? is starting with Y Therefore, the possible answers are (A) and (D). Similarly, let's specified the right option by checking their last letters Seem, consecutive R, S, T from left to right Hence the final right option is (A): YXZAS

deb, ijg, nol, (?), xyv (A) rsp (B) stp (C) rsq (D) stq The right option is D Explaination → All the letters of each term are moved five steps (+5) forward to obtain the corresponding letters of the next term.

A, Q, C, L, F, H, J, ? (A) rsp (B) stp (C) rsq (D) stq The right option is A Explaination → We have two series in this question First series :- First term = A Third term = First term +2 Fifth term = Third term +2 Seventh term = Fifth term +4 Ninth term = Seventh term +4 and so on Second series :- Second term = Q Fourth term = Second term -5 = L Sixth term = Fourth term -4 = H Eighth term = Sixth term -3 = E Tenth term = Eighth term -2 =D Hence E replaces question mark ?

BYCXW, CXDWV, EVFUT, GTHSR, ? (A) IRJQP (B) KPOLN (C) KPLON (D) JOKPO The right option is A Explaination → It is letter skipping correspondingly, Let's check with their first letters B +1 = C C +2 = E E +2 = G G +2 = I Here, the answer will start with letter I As there is only one option started with letter I, that is the right option but here we are not checking other letters though they might have variants of pettern.

FOX, GP?, HQZ (A) Y (B) Z (C) T (D) W The right option is A Explaination → It is a correspondingly letter skipping F +1 = G, G +1 = H O +1 = P, P +1 = Q Similarly, X +1 = Y, Y +1 = Z Hence, [A] Y is the right Answer.

QPO, SRQ, UTS, WVU, ? (A) XVZ (B) YXW (C) ZYA (D) VWX The right option is A Explaination → All the letters in each group are moved two steps forward, i.e WVU → YXW Hence, option A is the correct answer.

YEB, WFD, UHG, SKI, ? (A) QOL (B) TOL (C) QGL (D) QNL The right option is A Explaination → Clearly, the first letter of each term is moved two steps backward to obtain the first letter of the next term. So, the first letter of the missing term will be Q. The second letter of the first, second, third, fourth terms are respectively moved one, two, three and four steps forward to obtine the corresponding letter of the subsequent term. So, the second letter in the missing term will be O. The third letter is alternately moved two and three steps forward to obtain the corresponding letter of the subsequent term. So, the third letter in the missing term will be L. Thus, the missing term is QOL. Hence, the answer is (A).

AZ, CX, FU, ? (A) IR (B) JQ (C) IV (D) KP The right option is B Explaination → The given three terms are of two opposite pair letters So, the next term will also be paired letters By observing their first letter each 1st to 2nd letter is of +2 letters gap 2nd to 3rd letter is of +3 letters gap Hence, 3rd to 4th letter will be +4 letters gap Therefore, the required answer is JQ.

ABD, DGK, HMS, MTB, SBL, ? (A) ZAB (B) XKW (C) ZKU (D) ZKW The right option is D Explaination → It is letter skipping A +3 → D +4 → H +5 → M +6 → S +7 → Z B +5 → G +6 → M +7 → T +8 → B +9 → K D +7 → K +8 → S +9 → B +10 → L +11 → W Hence, the right answer is ZKW

OTE, PUF, QVG, RWH, ? (A) SYJ (B) TXI (C) SXJ (D) SXI The right option is D Explaination → All letters of each term increase +1 each to make the next term O +1 → P +1 → Q +1 → R +1 → S T +1 → U +1 → V +1 → W +1 → X E +1 → F +1 → G +1 → H +1 → I Hence, the right answer is SXI

BEH, KNQ, TWZ, ? (A) IJL (B) CFI (C) BDF (D) ADG The right option is B Explaination → It is of letter skipping and by observing, each corresponding letters of each terms are +9 gap B +9 → K +9 → T +9 → C E +9 → N +9 → W +9 → F H +9 → Q +9 → Z +9 → I Hence, the right answer is CFI

MHZ, NIW, OKT, PNQ, ? (A) RRN (B) QRN (C) QRM (D) QQN The right option is B Explaination → It is of letter skipping M +1 → N +1 → O +1 → P +1 → Q H +1 → I +2 → K +3 → N +4 → R Z -3 → W -3 → T -3 → Q -3 → N Hence, the right answer is QRN

A, CD, GHI, ?, UVWXY (A) LMNO (B) MNO (C) NOPQ (D) MNOP The right option is D Explaination → It is of letter skipping PLUS number of letter increasing 1st term is one letter 'A', so next one letter 'B' is skipped 2nd term is two letters 'CD', so next two letter 'EF' is skipped 3rd term is three letters 'GHI', so next three letters 'JKL' is skipped 4th term will be four letters i.e. 'MNOP' then next four letters 'QRST' is skipped 5th term is 'UVWXY' so, next five letters are skipped, and so on Hence, the right answer is MNOP

CAT, FDW, IGZ, ? (A) KJA (B) KTC (C) LHD (D) LJC The right option is D Explaination → C(+3) → F(+3) → I(+3) → L A(+3) → D(+3) → G(+3) → J T(+3) → W(+3) → Z(+3) → C Hence, the right answer is LJCb

1, 3, 8, 19, 42, 89, ? (A) 108 (B) 184 (C) 167 (D) 97 The right option is D Explaination → The series is as follows: 1 x 2 + 1 = 3 3 x 2 + 2 = 8 8 x 2 + 3 = 19 19 x 2 + 4 = 42 42 x2 +5 = 89 Then, 89 x 2 + 6 = 184 Hence, the right answer is 184

Find the missing term: 5, 16, 51, 158, ? (A) 1452 (B) 483 (C) 481 (D) 1454 The right option is D Explaination → The series is as follows: 5 × 3 + 1 = 16 16 × 3 + 3 = 51 51 × 3 + 5 = 158 158 × 3 + 7= 481 Hence, the right answer is 481

8, 13, 10, 15, 12, 17, 14...? (A) 19 (B) 22 (C) 16 (D) 20 The right option is A Explaination → There are two series alternatively: 8 (+2) → 10 (+2) → 12 (+2) → 14 similarly, 13 (+2) → 15 (+2) → 17 (+2) → 19 Hence, the right answer is 19

3, 15, 4, 16, 5, 17, 6, ?, 7 (A) 12 (B) 18 (C) 15 (D) 13 The right option is B Explaination → There are two series alternatively: 3 (+1) → 4 (+1) → 5 (+1) → 6 (+1) → 7 Similarly, 15 (+1) → 16 (+1) → 17 (+1) → 18 Hence, the right answer is 18

240, ?, 120, 40, 10, 2 (A) 480 (B) 240 (C) 220 (D) 120 The right option is B Explaination → There are two patterns: The first pattern is 1st÷1, 2nd÷2, 3rd÷3, 4th÷4, 5th÷5. The second pattern is 5 x 2 = 10 4 x 10 = 40 3 x 40 = 120 2 x 120 = 240 1 x 240 = 240 So, missing term = 240÷1 (OR 2 x 120) = 240. Hence, the right answer is 240

6.25, 9, 12.25, 16, 20.25, 25, 30.25, ? (A) 36 (B) 32 (C) 2825 (D) 4025 The right option is B Explaination → There are two series alternatively: The Second series is: 32 → 42 → 52 → 62 OR 9 (+7) → 16 (+9) → 25 (+11) → 36 The second series is: 6.25 (+6) → 12.25 (+8) → 20.25 (+10) → 30.25 So, missing term = 36. Hence, the right answer is 36

0, 7, 26, ?, 124, 215 (A) 51 (B) 37 (C) 63 (D) 16 The right option is C Explaination → The patterns are: 13 - 1 → 0 23 - 1 → 7 33 - 1 → 26 43 - 1 → 63 53 - 1 → 124 63 - 1 → 215 So, missing term = 63.

2, 12, 36, 80, 150, ? (A) 194 (B) 210 (C) 252 (D) 258 The right option is C Explaination → The patterns are: 12 + 13 → 2 22 + 23 → 12 32 + 33 → 36 42 + 43 → 80 52 + 53 → 150 62 + 63 → 252 So, missing term = 252.

1, 8, 9, 64, 25, 216, ?, ? (A) 49, 64 (B) 343, 64 (C) 49, 512 (D) 343, 512 The right option is C Explaination → There are two series: First patern: 1 9 25 ? 12 → 1 32 → 9 52 → 25 72 → 49 Similarly Second patern: 8 64 216 ? 23 → 8 43 → 64 63 → 216 83 → 512 So, missing term = 49, 512.

3, 13, 53, 213 ___? (A) 553 (B) 653 (C) 753 (D) 853 The right option is C Explaination → The pattern is: 3 x 4 + 1 = 13 13 x 4 + 1 = 53 53 x 4 + 1 = 213 213 x 4 + 1 = 853 So, missing term = 853.

4, 16, 36, ?, 100, 144 (A) 72 (B) 68 (C) 81 (D) 64 The right option is D Explaination → The pattern is: 22 → 4 42 → 16 62 → 36 82 → 64 102 → 100 122 → 144 So, missing term = 64.

8, 15, 28, 53, ? (A) 98 (B) 106 (C) 100 (D) 102 The right option is D Explaination → The pattern is: 2 x 4 - 0 = 8 2 x 8 - 1 = 15 2 x 15 - 2 = 28 2 x 28 - 3 = 53 2 x 53 - 4 = 102 So, missing term = 102.

6, 12, 21, ?, 48 (A) 38 (B) 40 (C) 45 (D) 33 The right option is D Explaination → The pattern is: 3 x 2 = 6 3 x 4 = 12 3 x 7 = 21 3 x 11 = 33 3 x 16 = 48 Here, 3 is common multiplier while 2, 4, 7, 11, 16 are number increment by +2, +3, +4, +5 So, missing term = 33.

1, 4, 27, 16, ?, 36, 343 (A) 87 (B) 120 (C) 25 (D) 125 The right option is D Explaination → It is of two channels: The first pattern of 1 27 ? 343 is: 13, 33, 53, 73 The second pattern of 4 16 36 is: 22, 42, 62 So, missing term = 125.

28, 33,31, 36, ? 39 (A) 32 (B) 34 (C) 38 (D) 40 The right option is B Explaination → It is of two channels: The first pattern of 28 31 ? is: 28 (+3) → 31, 31 (+3) → 34 The second pattern of 33 36 39 is: 33 (+3) → 36, 36 (+3) → 39 So, missing term = 34.

165, 195, 255, 285, 345, ? (A) 375 (B) 390 (C) 420 (D) 435 The right option is A Explaination → It can be of two channels as well as one channel: Dealing as one channel by difference checking: 165 (+30) → 195 (+60) → 255 (+30) → 285 (+60) → 345 (+30) → 375 So, missing term = 375.

1, 5, 14, 30, 55, 91, ? (A) 130 (B) 140 (C) 150 (D) 160 The right option is B Explaination → The pattern is: 12 + 0 = 1 22 + 1 = 5 32 + 5 = 14 42 + 14 = 30 52 + 30 = 55 62 + 55 = 91 72 + 91 = 140 So, missing term = 140.

625, 5, 125, 25, 25, ?, 5 (A) 5 (B) 25 (C) 125 (D) 625 The right option is C Explaination → It is of two channels: Second Channel from right to left 5 25 125 625 pattern is: 5 x 5 = 25 x 5 = 125 x 5 = 625 Similarly, First channel 5 25 ? is: 5 x 5 = 25 x 5 = 125 So, missing term = 125.

6, 18, 3, 21, 7, 56, ? (A) 8 (B) 9 (C) 63 (D) 64 The right option is A Explaination → Its pattern is: 6(1st) x 3(3rd) = 18(2nd) 3(3rd) x 7(5th) = 21(4th) Similarly, 7(5th) x ?((7th) = 56(6th) So, missing term = 8.

198, 194, 185, 169, ? (A) 136 (B) 144 (C) 9 (D) 92 The right option is B Explaination → Its pattern is: 198 - 194 = 4 (i.e. 22) 194 - 185 = 9 (i.e. 32) 185 - 169 = 16 (i.e. 42) 169 - ? = 25 (i.e. 52) So, missing term = 144.

4, 9, 25, ?, 121, 169, 289, 361 (A) 49 (B) 74 (C) 89 (D) 91 The right option is A Explaination → Its pattern is: 4=22 9=32 25=52 ?=?2 121=112 169=132 289=172 361=192 Since all are prime squaring So, missing term = (?2 = 72 = 49).

2, 5, 10, 17, 26, 37, ? (A) 61 (B) 58 (C) 50 (D) 72 The right option is C Explaination → Its pattern is by difference checking OR Addition: 2 + 3 = 5 5 + 5 = 10 10 + 7 = 17 17 + 9 = 26 26 + 11 = 37 Since the addition values are consecutive odd numbers. 37 + 13 = 50 So, missing term = 50.

24, 60, 120, 210, ? (A) 300 (B) 336 (C) 420 (D) 525 The right option is B Explaination → Its pattern is: 33 - 3 = 24 43 - 4 = 60 53 - 5 = 120 63 - 6 = 210 73 - 7 = 336 So, missing term = 336.

462, 420, 380, ?, 306 (A) 322 (B) 332 (C) 342 (D) 352 The right option is C Explaination → Its pattern is by checking difference: 462 - 420 = 42 420 - 380 = 40 380 - ? = 38 ? - 306 = 36 Since, the difference are consecutively decreasing by 2 i.e. 42, 40, 38, 36... So, missing term (?) = 342.

121, 225, 361, ? (A) 441 (B) 484 (C) 529 (D) 729 The right option is C Explaination → Its pattern is by checking perfect squaring: 121 = 112 225 = 152 361 = 192 529 = 232 Since, the differences are consecutively squaring of alternate odd i.e. 11, 15, 19 So, the next term (?) = (232) 529.

J2Z, K4X, I7V, ?, H16R, M22P (A) I11T (B) L11S (C) L12T (D) L11T The right option is D Explaination → It is of two series: The first series is J2Z, I7V, H16R J (-1) → I, I (-1) → H Simmilarly The Second series is K4X, ?, M22P J (+1) → K, K (+1) → L, L (+1) → M Here, the last letter will be: Z (-2) → X, X (-2) → V, V (-2) → T, T (-2) → R, R (-2) → P Now, we can say (B),(C),(D) are possible answer. Lets check further by the middle numerical value the mid numerical values seem increased like this: 2 (+2) = 4 4 (+3) = 7 7 (+4) = 11 11 (+5) = 16 16 (+6) = 22 So, the required value = L11T.

3F, 6G, 11I, 18L, ? (A) 21O (B) 25N (C) 27P (D) 27Q The right option is C Explaination → It is of two series, the numerical part and letters part: F (+1) → G G (+2) → I I (+3) → L L (+4) → P So, even by checking the letter part alone we can able to know the missing term = 27P.

KM5, IP8, GS11, EV14, ? (A) BXI7 (B) BY17 (C) CYI8 (D) CY17 The right option is D Explaination → Its pattern is: For first letter K (-2) → I I (-2) → G G (-2) → E E (-2) → C For second letter M (+3) → P P (+3) → S S (+3) → V V (+3) → Y For numerical values 5 (+3) → 8 8 (+3) → 11 11 (+3) → 14 14 (+3) → 17 So, the missing term = CY17.

Q1F, S2E, U6D, W21C, ? (A) Y44B (B) Y66B (C) Y88B (D) Z88B The right option is C Explaination → Its pattern is: For first letter Q (+2) → S S (+2) → U U (+2) → W W (+2) → Y Therefore, option A, B, C are possible answer. For numerical values 1 x 1 + 1 = 2 2 x 2 + 2 = 6 6 x 3 + 3 = 21 21 x 4 + 4 = 88 So, the missing term = Y88B.

2Z5, 7Y7, 14X9, 23W11, 34V13, ? (A) 27U24 (B) 45U15 (C) 47U15 (D) 47VI4 The right option is C Explaination → Its pattern is: For letter skipping: Z (-1) → Y Y (-1) → X X (-1) → W W (-1) → V V (-1) → U Therefore, option A, B, C are possible answer. For numerical values 2 + 5 = 7 7 + 7 = 14 14 + 9 = 23 23 + 11 = 34 34 + 13 = 47 So, the missing term = 47U15.

W-144, ?, S-100, Q-81, O-64 (A) U-121 (B) U-122 (C) V-121 (D) V-128 The right option is A Explaination → Its pattern is: For letter skipping: W (-2) → U U (-2) → S S (-2) → Q Q (-2) → O Therefore, option A, B are possible answer. For numerical values from right to left: 82 = 64 92 = 81 102 = 100 112 = 121 122 = 144 So, the missing term = U-121.

23B?6FG?5D?8?HI (A) C, 7, 4, E, 9 (B) D, 8, 6, C, 7 (C) E, 8, 7, D, 9 (D) W, 8, 7, 1, 6 The right option is A Explaination → Its pattern is: For letter skipping: BC FG DE HI So, the missing term = C, 7, 4, E, 9.

2A11, 4D13, 12G17, ? (A) 36J21 (B) 36119 (C) 48J21 (D) 48J23 The right option is D Explaination → Its pattern is: For letter skipping: A (+3) → D D (+3) → G G (+3) → J For numerical series: 2 x 2 = 4 4 x 3 = 12 12 x 4 = 48 And 11 (+2) = 13 13 (+4) = 17 17 (+6) = 23 So, the missing term = 48J23.

ba_b_aab_a_b (A) abaa (B) abba (C) baab (D) babb The right option is B Explaination → Its pattern is by mirror checking: Mirror checking in the sense, 1st letter and last letter will be same 2nd letter and 2nd from last will be same 3rd and 3rd form the last will be same and so on. So, correct answer = abba.

c _ bba _ cab _ ac _ ab _ ac (A) abcbc (B) acbcb (C) babcc (D) bcacb The right option is B Explaination → Its pattern is by mirror checking: Mirror checking in the sense, 1st letter and last letter will be same 2nd letter and 2nd from last will be same 3rd and 3rd form the last will be same and so on. So, correct answer = acbcb.

abca _ bcaab_ ca _ bbc _ a (A) ccaa (B) bbaa (C) abac (D) abba The right option is C Explaination → The pattern that complete the series is: abc | aabc | aabbc | aabbcc | a So, correct answer = abac.

b - b - bb - bbb - - bb - ba (A) bbbbba (B) bbaabb (C) ababab (D) aabaab The right option is C Explaination → The pattern that complete the series is: babb | bbab | bbba | bbbb | a So, correct answer = ababab.

aa – bb – aa – abbbb – a (A) bbaa (B) aabb (C) baba (D) abab The right option is A Explaination → The pattern can be completed by mirror checking: aa | bbbb | aaaa | bbbb | aa So, correct answer = bbaa.

– aba – cabc – dcba – bab – a (A) abdca (B) bcadc (C) abcdd (D) cbdaa The right option is A Explaination → The pattern can be completed by mirror checking: aa | bab | cab | cd | dc | bac | bab | aa So, correct answer = abdca.

aab - cc - daa - bbb - ccddd (A) bdbd (B) ddca (C) dbbc (D) bdac The right option is D Explaination → The pattern is : aabbccdd | aaabbbcccddd So, correct answer = bdac.

Find the wrong number 10 15 24 35 54 75 100 (A) 35 (B) 75 (C) 24 (D) 15 The right option is A Explaination → The pattern is by difference checking : So, correct answer = 35.

Find the wrong number 1 3 4 7 11 18 27 47 (A) 27 (B) 11 (C) 18 (D) 7 The right option is A Explaination → The pattern is : 1 + 3 = 4 3 + 4 = 7 4 + 7 = 11 7 + 11 = 18 11 + 18 = 29 (but it is 27) 18 + 29 = 47 It simply means: 1st term + 2nd term = 3rd term 2nd term + 3rd term = 4th term so on... So, wrong number = 27.

Find the wrong number 3 2 3 6 12 37.5 115.5 (A) 37.5 (B) 12 (C) 6 (D) 2 The right option is B Explaination → The pattern is : 3 x 0.5 + 0.5 = 2 2 x 1 + 1 = 3 3 x 1.5 + 1.5 = 6 6 x 2 + 2 = 14 (but it is 12) 14 x 2.5 + 2.5 = 37.5 37.5 x 3 + 3 = 115.5 So, wrong number = 12.

Find the wrong number 2 8 32 148 765 4626 32431 (A) 765 (B) 148 (C) 8 (D) 32 The right option is D Explaination → The pattern is : 2 x 2 + 22 = 8 8 x 3 + 32 = 33 (but it is 32) 33 x 4 + 42 = 148 148 x 5 + 52 = 765 765 x 6 + 62 = 4626 4626 x 7 + 72 = 32431 So, wrong number = 32.

Find the wrong number 2 3 11 38 102 229 443 (A) 11 (B) 229 (C) 120 (D) 38 The right option is B Explaination → The pattern is : 2 + 13 = 3 3 + 23 = 11 11 + 33 = 38 38 + 43 = 102 102 + 53 = 227 (but it is 226) 227 + 63 = 443 So, wrong number = 229.

Find the wrong number 5 10 17 27 37 50 65 (A) 10 (B) 17 (C) 27 (D) 37 The right option is C Explaination → The pattern is : 5 + 5 = 10 10 + 7 = 17 17 + 9 = 26 (but it is 27) 26 + 11 = 37 37 + 13 = 50 50 + 15 = 65 i.e. → It can also be done through difference checking Also, 22 + 1 = 5 32 + 1 = 10 42 + 1 = 17 52 + 1 = 26 (≠ 27) 62 + 1 = 37 72 + 1 = 50 82 + 1 = 65 So, wrong number = 27.

Find the wrong number 108 54 36 18 9 6 4 (A) 54 (B) 36 (C) 18 (D) 9 The right option is D Explaination → The pattern is : 108 ÷ 2 = 54 54 ÷ 1.5 = 36 36 ÷ 2 = 18 18 ÷ 1.5 = 12 (≠ 9) 12 ÷ 2 = 6 6 ÷ 1.5 = 4 So, wrong number = 9.

Find the wrong number 2 3 5 8 14 23 41 69 (A) 5 (B) 8 (C) 69 (D) 41 The right option is C Explaination → The pattern is : 2 x 3 - 1 = 5 3 x 3 - 1 = 8 5 x 3 - 1 = 14 8 x 3 - 1 = 23 14 x 3 - 1 = 41 23 x 3 - 1 = 68 (but it is 69) This means: 1st term x 3 - 1 = 3rd term 2nd term x 3 - 1 = 4th term So, wrong number = 69.

Find the wrong number 0 1 9 36 99 225 441 (A) 9 (B) 36 (C) 99 (D) 225 The right option is C Explaination → The pattern of 0 1 9 36 99 225 441 is : 02 = 0 12 = 1 32 = 9 62 = 36 102 = 100 (≠ 99) 152 = 225 212 = 441 So, wrong number = 99.

Find the wrong number 3 7.5 15 37.5 75 167.5 375 (A) 167.5 (B) 75 (C) 37.5 (D) 15 The right option is A Explaination → The pattern of 3 7.5 15 37.5 75 167.5 375 is : 3 x 2.5 = 7.5 7.5 x 2 = 15 15 x 2.5 = 37.5 37.5 x 2 = 75 75 x 2.5 = 187.5 (≠ 167.5) 187.5 x 2 = 375 So, wrong number = 167.5.

AKU, FPZ, ?, PZJ, UEO, ZJT (A) JUE (B) KVE (C) KUE (D) JVE The right option is C Explaination → The pattern is : First letter: A (+5) → F F (+5) → K K (+5) → P P (+5) → U U (+5) → Z So, possible answer is B & C Middle letter: K (+5) → P P (+5) → U U (+5) → Z Z (+5) → E E (+5) → J So, possible answer is C alone So, the missing term = KUE.

MRS, LTU, KVW, ? (A) TQR (B) MOP (C) JXY (D) CDE The right option is C Explaination → The pattern is : First letter: M (-1) → L L (-1) → K K (-1) → J So, possible answer is C alone So, missing term = JXY.

B, G, K, N, ? (A) P (B) O (C) H (D) L The right option is A Explaination → The pattern is : First letter: B (+5) → G G (+4) → K K (+3) → N N (+2) → P So, missing term = P.

1944, 108, ?, 6, 3 (A) 16 (B) 18 (C) 11 (D) 12 The right option is B Explaination → The pattern is : 3 x 6 = 18 6 x 18 = 108 18 x 108 = 1944 The pattern is: 1st term ÷ 2nd term = 3rd term OR 5th term x 4th term = 3rd term So, missing term = 18.

251 (12) 107 381 (?) 125 (A) 14 (B) 24 (C) 11 (D) 16 The right option is D Explaination → The pattern is : (251 - 107) = 144 (= 122) So, (381 - 125) = 256 (= 162) So, missing term = 16.

354 (110) 526 297 (?) 631 (A) 128 (B) 116 (C) 135 (D) 143 The right option is B Explaination → The pattern is : (354 + 526) ÷ 8 = 110 So, (297 + 631) ÷ 8 = 116 So, missing term = 116.

0, 7, 26, 63, ? (A) 125 (B) 126 (C) 217 (D) 124 The right option is D Explaination → The pattern is : 13 - 1 = 0 23 - 1 = 7 33 - 1 = 26 43 - 1 = 63 53 - 1 = 124 So, missing term = 124.

2, 5, 10, 19, 36, ? (A) 70 (B) 71 (C) 68 (D) 69 The right option is D Explaination → The pattern is : OR 2 x 2 + 1 = 5 5 x 2 ± 0 = 10 10 x 2 - 1 = 19 19 x 2 - 2 = 36 36 x 2 - 3 = 69 So, missing term = 69.

Which one set of letters when sequentially placed at the gaps in the given letter series shall complete it? a _ cbc _ca _ ab _bca _ ab (A) babcc (B) bcabb (C) abcbc (D) bcabc The right option is A Explaination → The pattern is : abc | bca | cab | abc | bca | cab So, right answer = babcc.

Complete the series BCFG, JKNO, RSVW, ? (A) ZADE (B) HIKL (C) STUSX (D) MNPQ The right option is A Explaination → The pattern is : BC(de)FG, (hi) JK(lm)NO, (pq) RS(tu)VW, (xy) ZA(bc)DE So, right answer = ZADE.

Complete the series CIM, HNR, MSW, ? (A) SXA (B) UYB (C) RXB (D) ZEH The right option is C Explaination → The pattern is : LETTER SKIPPING OF FIRST LETTER C (+5) → H H (+5) → M M (+5) → R So, right answer = RXB.

Complete the series 2, 3, 6, 7, 14, 15, ? (A) 16 (B) 30 (C) 31 (D) 32 The right option is B Explaination → The pattern is : So, right answer = 30.

Complete the series 3120, ?, 122, 23, 4 (A) 488 (B) 621 (C) 610 (D) 732 The right option is B Explaination → The pattern is : 4 x 5 + 3 = 23 23 x 5 + 7 = 122 122 x 5 + 11 = 621 621 x 5 + 15 = 3120 So, right answer = 621.

Complete the series 0, 5, 60, 615, ? (A) 6030 (B) 6170 (C) 6130 (D) 6000 The right option is B Explaination → The pattern is : 0 x 10 + 5 = 5 5 x 10 + 10 = 60 60 x 10 + 15 = 615 615 x 10 + 20 = 6170 OR So, right answer = 6170.

Which one set of letters when sequentially placed at the gaps in the given letter series shall complete it? ac_c _ cb _ acbcacbca _ bc (A) abbb (B) bacc (C) babc (D) bbcc The right option is B Explaination → The pattern is able to detect out from unblank area "acbcacbca" : So, it is acbc | acbc | acbc | acbc | acbc So, right answer = bacc.

Which one set of letters when sequentially placed at the gaps in the given letter series shall complete it? rtx _ sx_z_ txy _ yz (A) yyrxs (B) yysxr (C) yyrsx (D) yyxrs The right option is C Explaination → The pattern is able to detect out from unblank area "acbcacbca" : So, it is rtxysxyz | rtxysxyz So, right answer = yyrsx.

Complete the series 1, 2, 6, 24, ?, 720 (A) 3 (B) 5 (C) 120 (D) 8 The right option is C Explaination → Here, 1 x 2 = 2 2 x 3 = 6 6 x 4 = 24 24 x 5 = 120 120 x 6 = 720 OR Just by observing the question and the answer options we can simply say that the required term is greater than 24 So, 120 is the only possible term among the options. So, right answer = 120.

Complete the series 156, 506, ?, 1806 (A) 1056 (B) 856 (C) 1456 (D) 1506 The right option is A Explaination → Here, So, right answer = 1056.

Complete the series 3, 6, 9, 15, 24, 39, 63, ? (A) 100 (B) 87 (C) 102 (D) 99 The right option is C Explaination → Here, 3 + 6 = 9 6 + 9 = 15 9 + 15 = 24 15 + 24 = 39 24 + 39 = 63 39 + 63 = 102 By difference checking: So, right answer = 102.

Complete the series -1, 0, ?, 8, 15, 24 (A) 4 (B) 3 (C) 2 (D) 1 The right option is B Explaination → Here, -1 + 1 = 0 0 + 3 = 3 3 + 5 = 8 8 + 7 = 15 15 + 9 = 24 By difference checking: So, right answer = 3.