# 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
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
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
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
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
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
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
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
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
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
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

## 10 Thoughts to “Quantitative Aptitude: Number Series 35”

1. chinnu

ma’am in 1st questn instead of 5 (second) 6.5 and in 4th ques 3335 instead of 3325

1. Banya

yes .. now it is corrected.

2. Chotu D(mind) !! {NONSENSE}

done..9/10

3. kumkum ahuja

ty az

4. Mission RRB PO

mam
check ques 8th

1. Banya

corrected

1. Mission RRB PO

thanks 🙂

5. jaga

mam q8 wrong hai.

1. Banya

corrected.