Quantitative Aptitude: Number Series Set 98

Directions(1-5): Find the missing term '?' of the following series.

1. 81, 82, 42, 15, ?
   3.33
   2.50
   4.75
   6.16
   2.87
   Option C
   Pattern is 81+1/ 1 , 82+2 /2 , 42+3/ 3 , 15+4/ 4 = 4.75
   
    



2. 8, 7, 11, 12, 14, 17, 17, 22, ?
   12
   18
   22
   20
   15
   Option D
   Two series are there. I.e. (8, 11, 14, 17, 20) and (7, 12, 17, 22) increasing by 3 and 5
   ? = 20
   
   
    



3. 1, 5, 14, 30, 55, 91, ?
   124
   138
   140
   156
   178
   Option C
   Pattern is +2 ^2 , +3 ^2 , +4^ 2 , +5^ 2 … ….
   ? = 91 + 7^2 = 140
   
   
    



4. 11, 29, 83, 245, 731, ?
   1881
   2020
   1562
   1992
   2189
   Option E
   Series is × 3 − 4
   ? = 731 × 3 − 4 = 2189
   
   
    



5. 4, 1, 0.5, 0.5, 1, ?
   9
   4
   5
   8
   6
   Option B
   Series is ×0.25, ×0.5, ×1, ×2, ×4
   ? = 4
   
   
    



6. 6, 9, 18, 45, 126, ?
   313
   369
   350
   320
   309
   Option B
   Series is +3^ 1 , +3^ 2 , +3^ 3 , +3 ^4 , +3 ^5
   ? = 126 + 243 = 369
   
   
    



7. 3, 8, 20, 46, 100, 210, ?
   389
   400
   356
   432
   411
   Option D
   Series is as × 2 + 2,× 2 + 4,× 2 + 6,× 2 + 8,× 2 + 10,× 2 + 12
   ? = 210 × 2 + 12 = 432
   
   
    



8. 2, 4.5, 9.5, 19.5, 39.5, ?
   81.8
   67.7
   55.5
   79.5
   67.1
   Option D
   Series is +2.5, +5, +10, +20, +40
   ? = 39.5 + 40 = 79.5
   
   
    



9. 5, 7, 17, 55, 225, 1131, ?
   6617
   5647
   6793
   9927
   8163
   Option C
   Series is as, × 1 + 2,× 2 + 3,× 3 + 4,× 4 + 5,× 5 + 6,× 6 + 7
   ? = 1131 × 6 + 7 = 6793
   
   
    



10. 677, 785, 901, 1025, ? , 1297
    1245
    1728
    1452
    1157
    1900
    Option D
    26² + 1 = 677
    28² + 1 = 785
    30² + 1 = 901
    32² + 1 = 1025
    34² + 1 = 1157
    36² + 1 = 1297
    ? = 1157