Quantitative Aptitude: Number Series 35

Quantitative Aptitude Questions for IBPS RRB/PO/Clerk, SBI PO, NIACL, NICL, RBI Grade B/Assistant, UIICL, OICL and other competitive exams.

Directions(1-5): What will come in the place of the question mark (?) in the following number series ?

1. 14      6      5       6.5      12     ?
   A) 22
   B) 20
   C) 25
   D) 29
   E) 30
   
   View Answer

     Option D
   Solution:
   14 *(1/2) – 1 = 7 – 1 = 6
   6 * 1 – 1 = 6 – 1 = 5
   5 *(3/2) – 1 = 7.5 – 1 = 6.5
   6.5 *(4/2) – 1 = 13 – 1 = 12
   12 *(5/2) – 1 = 30 – 1 = 29
   
2. 47      23     11       5       2      ?
   A) 0.5
   B) 1.15
   C) 2.5
   D) 1.25
   E) 3.5
   
   View Answer

     Option A
   Solution:
   (47-1)/2 = 46/2 = 23
   (23-1)/2 = 22/2 = 11
   (11-1)/2 = 10/2 = 5
   (5-1)/2 = 4/2 = 2
   (2-1)/2 = ½ = 0.5
   
   
3. 1     3    10     ?     152    770    4632
   A) 40
   B) 15
   C) 30
   D) 36
   E) 43
   
   View Answer

     Option C
   Solution:
   1*1 +2 =3
   3*2+4=10
   10*3+6=36
   36*4+8=152
   152*5+8=770
   770*6+12=4632
   
4. 4      5      9      ?      111      556        3335
   A) 20
   B) 28
   C) 18
   D) 22
   E) 13
   
   View Answer

     Option B
   Solution:
   4 *1+1 = 5
   5*2-1 = 9
   9*3 +1 =28
   28*4-1=111
   111*5+1=556
   556*6-1=3335
5. 10    15    30     75     ?     787.5
   A) 180
   B) 200
   C) 210
   D) 150
   E)225
   
   View Answer

     Option E
   Solution:
   10*1.5 = 15
   15*2=30
   30*2.5=75
   75*3=225
   225*3.5=787.5
   
   Directions(6-10): In the following number series only one number is wrong. Find out the wrong  number.
6. 39     43    55     60    87    103     167
   A) 103
   B) 55
   C) 43
   D) 60
   E) 39
   
   View Answer

     Option B
   Solution:
   39 +2^2 = 39 + 4 = 43
   43 + 2^3 = 43 + 8 = 51
   51 + 3^2 = 51 + 9 = 60
   60 + 3^3 = 60 + 27 = 87
   87 + 4^2 = 87 + 16 = 103
   103 + 4^3 = 103 + 64 = 167
7. 158    77     38    18    8     3
   A) 3
   B) 18
   C) 8
   D) 77
   E) 158
   
   View Answer

     Option  D
   Solution:
   (158/2) – 1 = 79 – 1 = 78
   (78/2) – 1 = 39 – 1 = 38
   (38/2) – 1 = 19 – 1 = 18
   (18/2) – 1 = 9 – 1 = 8
   (8/2) – 1 = 4 – 1 = 3
   
8. 16       15       19      10       26       2       37
   A) 26
   B) 2
   C) 10
   D) 16
   E) 15
   
   View Answer

     Option B
   Solution:
   16 – 1^2 = 15
   15  + 2^2 = 19
   19 – 3^2 = 10
   10 + 4^2 = 26
   26 – 5^2 = 1
   1 +  6^2 = 37
   
9. 20     23     30     44     64     95
   A) 44
   B) 20
   C) 64
   D) 30
   E) 95
   
   View Answer

     Option A
   Solution:
   20 + 3 = 23
   23 + 7 (=3+4) = 30
   30 + 13 (=7+6) = 43
   43 + 21(=13+6) = 64
   64 + 31 (=21 +10) = 95
   
10.  4      5.8     10.5     16.6       14.4        59.8
    A) 14.4
    B) 5.8
    C) 4
    D) 10.5
    E) 59.8
    
    View Answer

      Option D
    Solution:
    4 + 1.8 *1= 4 + 1.8 = 5.8
    5.8 + 1.8 *2 = 5.8 + 3.6 = 9.4
    9.4 + 3.6 *2 = 9.4 + 7.2 = 16.6
    16.6 +7.2*2 = 16.6 + 14.4= 31
    31 + 14.4*2 = 31 + 28.8 = 59.8
    

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