# Number Series Practice Questions for SBI PO

Number Series Practice Questions for SBI PO
Directions (1 – 5): What will come in place of question mark (?) in the following number series?
1. 281 218 163 116 ?
a) 77
b) 78
c) 56
d) 52
e) 85
2. 900 810 440 392 180 ?
a) 48
b) 150
c) 90
d) 45
e) 78
3. 57 73 91 111 ? 157.
a) 143
b) 133
c) 123
d) 135
e) None of these
4. 57 85 105 117 ?
a) 121
b) 108
c) 138
d) 136
e) 135
5. 39 48 53 54 51 ?
a) 59
b) 44
c) 33
d) 46
e) 48
Directions (6 – 10): In each of these questions a number series is given. In each series only one number is wrong. Find the wrong number.
6. 3 16 19 46 55 92 105
a) 3
b) 19
c) 46
d) 92
e) 105
7. 3 12 30 60 108 168 252
a) 12
b) 30
c) 108
d) 168
e) 252
8.1/3 1/2 3/5 2/3 6/7 6/8 8/9
a) 1/3
b) 1/2
c) 3/5
d) 2/3
e) 6/7
9. 10 21 36 56 78 105 136
a) 10
b) 56
c) 78
d) 105
e) 136
10. 100 80 64 51.2 40.5 32.768 26.2144 20.97152
a) 40.5
b) 64
c) 32.768
d) 26.2144
e) 20.97152
Solutions:
1. The series is 172 8 , 152 7 , 132 6, 112 5 , 92 4 , 72 3 , ……..
2. The series is 103 - 102 = 900, 93 + 92 = 810, 83 82 = 448 , 73 + 72 = 392, 63 62 = 180, 53 + 52= 150
, ………..
3. The series is 72 + 8 = 57, 82 + 9 =73, 92 +10 = 91, 102 + 11= 111, 112 + 12 = 133, 122 + 13= 157,
132 + 14 = 183,..
4. The series is 6 × 9.5 = 57, 10 × 8.5 = 85, 14 × 7.5 = 105, 18 × 6.5 =117, 22 × 5.5 = 121, 26 × .5 =
117,.
5. The series is 6 × 9 15 = 39, 8 × 8 16 = 48, 10 × 7 17 = 53, 12 × 6 18 = 54, 14 × 5 19 = 51,
16 × 4 20 = 44, 18 × 3 -21 = 33,…….
6. The series is 12 + 22 2, 22 + 32 + 3, 32 + 42 4, 42 + 52 + 5, 52 + 62 6, 62 + 72 + 7, 72 + 82 - 8.
Hence there should be 21 in place of 19.
7. The series is (1×2×3)/2, (2×3×4)/2, (3×4×5)/2, (4×5×6)/2, (5×6×7)/2, (6×7×8)/2, (7×8×9)/2
= 3, 12, 30, 60, 105, 168, 252
Hence there should be 105 in place on 108.