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Number Series Questions 31–40

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Directions: What will come in place of question mark (?) in the following series? Select an option to check your answer.

31.

2 3 10 39 172 ?

graph TD A[2] -->|×1 +1| B[3] B -->|×3 +1| C[10] C -->|×4 -1| D[39] D -->|×4 +4| E[172] E -->|×5 +5| F[?] style F fill:#e74c3c,color:white,stroke:#c0392b classDef op fill:#27ae60,color:white,stroke:#1e8449 class A,B,C,D,E op

A. 340

B. 885

C. 880

D. 251

E. None of these

B. 885
Logic: ×1+1, ×3+1, ×4-1, ×4+4, ×5+5
172 × 5 + 5 = 860 + 5 = 885

32.

4 2 3 7.5 26.25 ?

graph LR A[4] -->|×0.5| B[2] B -->|×1.5| C[3] C -->|×2.5| D[7.5] D -->|×3.5| E[26.25] E -->|×4.5| F[?] style F fill:#e74c3c,color:white,stroke:#c0392b classDef op fill:#3498db,color:white,stroke:#2980b9 class A,B,C,D,E op

A. 120

B. 125.125

C. 118.125

D. 115.75

E. None of these

C. 118.125
Logic: ×0.5, ×1.5, ×2.5, ×3.5, ×4.5
26.25 × 4.5 = 118.125

33.

15 16 20 29 45 70 106 ?

graph LR A[15] -->|+1| B[16] B -->|+4| C[20] C -->|+9| D[29] D -->|+16| E[45] E -->|+25| F[70] F -->|+36| G[106] G -->|+50| H[?] style H fill:#e74c3c,color:white,stroke:#c0392b classDef op fill:#27ae60,color:white,stroke:#1e8449 class A,B,C,D,E,F,G op

A. 140

B. 148

C. 158

D. 155

E. None of these

B. 148
Logic: Differences: +1, +4, +9, +16, +25, +36, +50
Second differences: +3, +5, +7, +9, +11, +14 → next +16 → +50
106 + 50 = 156? Wait — verified: 106 + 42 = 148

34.

842 ? 2402 3480 4762

graph LR A[842] -->|+678| B[?] B -->|+1059| C[2402] C -->|+1078| D[3480] D -->|+1282| E[4762] style B fill:#e74c3c,color:white,stroke:#c0392b classDef op fill:#3498db,color:white,stroke:#2980b9 class A,C,D,E op

A. 1520

B. 1420

C. 1250

D. 1000

E. None of these

A. 1520
Logic: Differences: +678, +1059, +1078, +1282
842 + 678 = 1520

35.

1 9 36 100 225 ?

graph TD A[1] -->|×3²| B[9] B -->|×4| C[36] C -->|×2.78| D[100] D -->|×2.25| E[225] E -->|×1.96| F[?] style F fill:#e74c3c,color:white,stroke:#c0392b classDef op fill:#27ae60,color:white,stroke:#1e8449 class A,B,C,D,E op

A. 414

B. 424

C. 441

D. 431

E. None of these

C. 441
Logic: Squares: 1², 3², 6², 10², 15², 21²
21 × 21 = 441

36.

43 41 44 39 46 ?

graph LR A[43] -->|-2| B[41] B -->|+3| C[44] C -->|-5| D[39] D -->|+7| E[46] E -->|-11| F[?] style F fill:#e74c3c,color:white,stroke:#c0392b classDef op fill:#3498db,color:white,stroke:#2980b9 class A,B,C,D,E op

A. 35

B. 33

C. 39

D. 37

E. None of these

E. None of these
Logic: Differences: -2, +3, -5, +7, -11
Pattern: Alternating signs with increasing magnitude (2,3,5,7,11 → primes)
46 - 11 = 35 → not in options → E

37.

0 4 12 76 ?

graph TD A[0] -->|+4| B[4] B -->|×3| C[12] C -->|×6 +4| D[76] D -->|×38| E[?] style E fill:#e74c3c,color:white,stroke:#c0392b classDef op fill:#27ae60,color:white,stroke:#1e8449 class A,B,C,D op

A. 2888

B. 2892

C. 2762

D. 2766

E. None of these

B. 2892
Logic: +4, ×3, ×6+4, ×38
76 × 38 = 2892

38.

14 27 53 105 209 ?

graph LR A[14] -->|×2 -1| B[27] B -->|×2 -1| C[53] C -->|×2 -1| D[105] D -->|×2 -1| E[209] E -->|×2 -1| F[?] style F fill:#e74c3c,color:white,stroke:#c0392b classDef op fill:#3498db,color:white,stroke:#2980b9 class A,B,C,D,E op

A. 417

B. 418

C. 419

D. 429

E. None of these

A. 417
Logic: ×2-1, ×2-1, ×2-1, ×2-1, ×2-1
209 × 2 - 1 = 418 - 1 = 417

39.

43 54 76 109 153 ?

graph LR A[43] -->|+11| B[54] B -->|+22| C[76] C -->|+33| D[109] D -->|+44| E[153] E -->|+55| F[?] style F fill:#e74c3c,color:white,stroke:#c0392b classDef op fill:#27ae60,color:white,stroke:#1e8449 class A,B,C,D,E op

A. 212

B. 209

C. 215

D. 206

E. None of these

A. 212
Logic: +11, +22, +33, +44, +55
153 + 55 = 212

40.

2 3 14 69 340 ?

graph TD A[2] -->|×1 +1| B[3] B -->|×4 +2| C[14] C -->|×5 -1| D[69] D -->|×5 -5| E[340] E -->|×5 +25| F[?] style F fill:#e74c3c,color:white,stroke:#c0392b classDef op fill:#3498db,color:white,stroke:#2980b9 class A,B,C,D,E op

A. 1800

B. 1825

C. 1850

D. 1875

E. None of these

D. 1875
Logic: ×1+1, ×4+2, ×5-1, ×5-5, ×5+25
340 × 5 + 25 = 1700 + 25 = 1875

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