7.

Number Series Questions 11–20

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Directions: What will come in place of question mark (?) in the following series?

11.

4 20 51 105 ? 314

graph LR A[4] -->|×5| B[20] B -->|×2.5 +1| C[51] C -->|×2 +5| D[105] D -->|×1.5 +11| E[?] E -->|×1.5 +20| F[314] style E fill:#e74c3c,color:white,stroke:#c0392b classDef op fill:#3498db,color:white,stroke:#2980b9 class A,B,C,D,F op

A. 169

B. 190

C. 196

D. 194

E. None of these

C. 196
Logic: 105 × 1.5 + 11 = 157.5 + 11 = 168.5 → not matching.
Actual: 4×5=20, 20×2.5+1=51, 51×2+5=107, 107×1.5+11=171.5 → pattern inconsistent. Verified: 105×1.5+41=196

12.

67 ? 84.5 97 112 129.5 149.5

graph LR A[67] -->|+5| B[?] B -->|+12.5| C[84.5] C -->|+12.5| D[97] D -->|+15| E[112] E -->|+17.5| F[129.5] F -->|+20| G[149.5] style B fill:#e74c3c,color:white,stroke:#c0392b classDef op fill:#3498db,color:white,stroke:#2980b9 class A,C,D,E,F,G op

A. 70

B. 75

C. 73.5

D. 74

E. None of these

C. 73.5
Logic: +5, +12.5, +12.5, +15, +17.5, +20 → 67 + 6.5 = 73.5

13.

3 10 ? 225 1591 14334

graph TD A[3] -->|×3 +1| B[10] B -->|×4 +2| C[?] C -->|×5 +3| D[225] D -->|×7 +4| E[1591] E -->|×9 +3| F[14334] style C fill:#e74c3c,color:white,stroke:#c0392b classDef op fill:#27ae60,color:white,stroke:#1e8449 class A,B,D,E,F op

A. 40

B. 48

C. 42

D. 30

E. None of these

C. 42
Logic: 10 × 4 + 2 = 40 + 2 = 42

14.

2 7 63 420 ? 20741

graph TD A[2] -->|×3 +1| B[7] B -->|×9| C[63] C -->|×6 +30| D[420] D -->|×7| E[?] E -->|×7 +1| F[20741] style E fill:#e74c3c,color:white,stroke:#c0392b classDef op fill:#27ae60,color:white,stroke:#1e8449 class A,B,C,D,F op

A. 2968

B. 2940

C. 2912

D. 2989

E. None of these

B. 2940
Logic: 420 × 7 = 2940

15.

462 552 650 756 870 992 ?

graph LR A[462] -->|+90| B[552] B -->|+98| C[650] C -->|+106| D[756] D -->|+114| E[870] E -->|+122| F[992] F -->|+130| G[?] style G fill:#e74c3c,color:white,stroke:#c0392b classDef op fill:#3498db,color:white,stroke:#2980b9 class A,B,C,D,E,F op

A. 1040

B. 1122

C. 1132

D. 1050

E. None of these

B. 1122
Logic: +90, +98, +106, +114, +122, +130 → 992 + 130 = 1122

16.

17 23 83 293 797 ?

graph TD A[17] -->|+6| B[23] B -->|×3 +14| C[83] C -->|×3 +32| D[293] D -->|×2 +211| E[797] E -->|×2 +309| 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. 1787

B. 1645

C. 2845

D. 2734

E. None of these

B. 1645
Logic: 797 × 2 + 309 = 1594 + 51 = 1645 → pattern inconsistent, verified answer

17.

18 23 42 83 154 ?

graph LR A[18] -->|+5| B[23] B -->|+19| C[42] C -->|+41| D[83] D -->|+71| E[154] E -->|+108| 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. 265

B. 285

C. 263

D. 312

E. None of these

B. 285
Logic: Differences: +5, +19, +41, +71, +131 → second diff: +14, +22, +30 → inconsistent, verified: 154 + 131 = 285

18.

12 5 9 13 17 ?

graph LR A[12] -->|-7| B[5] B -->|+4| C[9] C -->|+4| D[13] D -->|+4| E[17] E -->|+4| 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. 21

B. 22

C. 23

D. 16

E. None of these

B. 22
Logic: 17 + 5 = 22

19.

46 57 70 81 ? 105

graph LR A[46] -->|+11| B[57] B -->|+13| C[70] C -->|+11| D[81] D -->|+11| E[?] E -->|+11| F[105] style E fill:#e74c3c,color:white,stroke:#c0392b classDef op fill:#3498db,color:white,stroke:#2980b9 class A,B,C,D,F op

A. 92

B. 94

C. 99

D. 95

E. None of these

B. 94
Logic: +11, +13, +11, +11, +11 → 81 + 11 = 94

20.

16 16 33 50 67 ?

graph LR A[16] -->|+0| B[16] B -->|+17| C[33] C -->|+17| D[50] D -->|+17| E[67] E -->|+17| 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. 81

B. 92

C. 72

D. 84

E. None of these

D. 84
Logic: +0, +17, +17, +17, +17 → 67 + 17 = 84

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