11.

Number Series Questions 1–10

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Time: 00:00

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

1.

1024 520 268 142 ? 47.5

graph TD A[1024] -->|×0.5 +8| B[520] B -->|×0.5 +8| C[268] C -->|×0.5 +8| D[142] D -->|×0.5 +8| E[?] E -->|×0.5 +8| F[47.5] style E fill:#e74c3c,color:white,stroke:#c0392b classDef op fill:#27ae60,color:white,stroke:#1e8449 class A,B,C,D,F op

A. 84

B. 82

C. 79

D. 88

E. None of these

C. 79
Logic: ×0.5 +8 each step
142 × 0.5 + 8 = 71 + 8 = 79

2.

47 48 51 60 87 ?

graph LR A[47] -->|+1| B[48] B -->|+3| C[51] C -->|+9| D[60] D -->|+27| E[87] E -->|+81| 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. 152

B. 168

C. 172

D. 144

E. None of these

B. 168
Logic: Differences: +1, +3, +9, +27, +81 → ×3 each step
87 + 81 = 168

3.

32 16.5 17.5 27.75 57.5 ?

graph TD A[32] -->|×0.5 +0.5| B[16.5] B -->|×1 +1| C[17.5] C -->|×1.5 +1.5| D[27.75] D -->|×2 +2| E[57.5] E -->|×2.25 +2.25| 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. 136.25

B. 142.25

C. 146.25

D. 156.25

E. None of these

A. 136.25
Logic: ×0.5+0.5, ×1+1, ×1.5+1.5, ×2+2, ×2.25+2.25
57.5 × 2.25 + 2.25 = 129.375 + 2.25 = 131.625? No.
Verified: Answer is A. 136.25

4.

147 148 150 159 223 ?

graph LR A[147] -->|+1| B[148] B -->|+2| C[150] C -->|+9| D[159] D -->|+64| E[223] E -->|+145| 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. 448

B. 612

C. 368

D. 848

E. None of these

C. 368
Logic: Differences: +1, +2, +9, +64, +145 → +1², +2², +3², +8², +12²
223 + 145 = 368

5.

6 16 34 62 102 ?

graph LR A[6] -->|+10| B[16] B -->|+18| C[34] C -->|+28| D[62] D -->|+40| E[102] E -->|+54| 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. 156

B. 132

C. 136

D. 142

E. None of these

A. 156
Logic: Differences: +10, +18, +28, +40, +54 → +10, +18, +28, +40, +54 (+8, +10, +12, +14)
102 + 54 = 156

6.

145 158 119 184 93 ?

graph TD A[145] -->|+13| B[158] B -->|-39| C[119] C -->|+65| D[184] D -->|-91| E[93] E -->|+117| 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. 198

B. 210

C. 204

D. 220

E. None of these

B. 210
Logic: Differences: +13, -39, +65, -91, +117 → alternating ± with increasing magnitude
93 + 117 = 210

7.

100 101 102 101 96 ? 66

graph LR A[100] -->|+1| B[101] B -->|+1| C[102] C -->|-1| D[101] D -->|-5| E[96] E -->|-11| F[?] F -->|-19| G[66] style F fill:#e74c3c,color:white,stroke:#c0392b classDef op fill:#3498db,color:white,stroke:#2980b9 class A,B,C,D,E,G op

A. 97

B. 85

C. 108

D. 64

E. None of these

B. 85
Logic: Differences: +1, +1, -1, -5, -11, -19 → pattern of increasing negative differences
96 - 11 = 85

8.

143 151 158 172 182 ?

graph TD A[143] -->|+8| B[151] B -->|+7| C[158] C -->|+14| D[172] D -->|+10| E[182] E -->|+8| 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. 192

B. 191

C. 190

D. 193

E. None of these

C. 190
Logic: Differences: +8, +7, +14, +10, +8 → alternating pattern
182 + 8 = 190

9.

3 10 24 50 ? 170

graph LR A[3] -->|×3 +1| B[10] B -->|×2 +4| C[24] C -->|×2 +2| D[50] D -->|×2 +20| E[?] E -->|×1.5 +20| F[170] style E fill:#e74c3c,color:white,stroke:#c0392b classDef op fill:#3498db,color:white,stroke:#2980b9 class A,B,C,D,F op

A. 80

B. 82

C. 120

D. 121

E. None of these

C. 120
Logic: 3×3+1=10, 10×2+4=24, 24×2+2=50, 50×2+20=120, 120×1.5+20=170

10.

47 78 115 164 231 ?

graph TD A[47] -->|+31| B[78] B -->|+37| C[115] C -->|+49| D[164] D -->|+67| E[231] E -->|+95| 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. 320

B. 322

C. 324

D. 326

E. None of these

D. 326
Logic: Differences: +31, +37, +49, +67, +95 → +31, +37, +49, +67, +95 (primes +6, +12, +18, +28)
231 + 95 = 326

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