Aptitude Questions: Number Series Set 39

Hello Aspirants. Welcome to Online Quantitative Aptitude Section in AffairsCloud.com. Here we are creating question sample in Number Series, which is common for all the competitive exams. We have included Some questions that are repeatedly asked in bank exams !!!

Directions(1-10) : In these questions, a number series is given. Find out the missing number.

1. 18 10 8 9 11.5 ?
   A. 14.75
   B. 10.75
   C. 18.75
   D. 19.75
   E. 20.75
   

   Answer & Explanation

   Answer – A. 14.75
   Explanation :
   18 / 2 + 1 = 10
   10 / 2 + 3 = 8
   8 / 2 + 5 = 9
   
   
2. 6 4 6 12 22 ? 
   A. 26
   B. 36
   C. 86
   D. 66
   E. 46
   

   Answer & Explanation

   Answer – B. 36
   Explanation :
   6 / 2 + 1² = 4
   4 / 2 + 2² = 6
   6 / 2 + 3² = 12….
   
   
3. 20 39 74 ? 262 499 
   A. 146
   B. 169
   C. 166
   D. 139
   E. 129
   

   Answer & Explanation

   Answer – D. 139
   Explanation :
   20*2 – 1² = 39
   39*2 – 2² = 74
   74*2 – 3² = 139…..
   
   
4. 15 32 60 122 240 ?
   A. 362
   B. 488
   C. 482
   D. 364
   E. 382
   

   Answer & Explanation

   Answer – C. 482
   Explanation :
   15 * 2 + 2 = 32
   32 * 2 – 4 = 60
   60 * 2 + 2 = 122; 122 * 2 – 4 = 240…
   
   
5. 14 12 28 78 320 ?
   A. 1450
   B. 1590
   C. 1440
   D. 1810
   E. 1690
   

   Answer & Explanation

   Answer – B. 1590
   Explanation :
   14 * 1 – 2 = 12
   12 * 2 + 4 = 28
   28 * 3 – 6 = 78; 78 * 4 + 8 = 320; 320 * 5 – 10 = 1590
   
   
6. 31, 16, 10, 13, 38.5, ?
   A. 167.25
   B. 177.25
   C. 147.25
   D. 174.25
   E. 185.25
   

   Answer & Explanation

   Answer – C. 147.25
   Explanation :
   31 / 2 + 0.5 = 16
   16 / 2 + 2 = 10
   10 / 2 + 8 = 13
   13 / 2 + 32 = 38.5…..
   
   
7. 25 25 37 57 113 ?
   A. 202
   B. 207
   C. 185
   D. 195
   E. 190
   

   Answer & Explanation

   Answer – C. 185
   Explanation :
   25 + 1² – 1 = 25
   25 + 3² + 3 = 37
   37 + 5² – 5 = 57…..
   
   
8. 18, 20, 40, 70, 142 ?
   A. 232
   B. 254
   C. 188
   D. 196
   E. 240
   

   Answer & Explanation

   Answer – A. 232
   Explanation :
   18 + 2² – 2 = 20; 20 + 4²+ 4 = 40; 40 + 6² – 6 = 70 ….
   
   
9. 720 520 336 222 120 ?
   A. 78
   B. 68
   C. 76
   D. 56
   E. 58
   

   Answer & Explanation

   Answer – B. 68
   Explanation :
   9³ – 9 = 720
   8³ + 8 = 520
   7³ – 7 = 336
   6³ + 6 = 222….
   
   
10. 72, 72, 42, 42, 20, ?
    A. 30
    B. 40
    C. 50
    D. 20
    E. 10
    

    Answer & Explanation

    Answer – D. 20
    Explanation :
    9² – 9 = 72
    8² + 8 = 72
    7² – 7 = 42
    6² + 6 = 42