Quantitative Aptitude: Number Series

Directions: What will come in place of (?) in the following series which follows a particular pattern?

1.                     7, 5, 7, 17, 63, 309, ?
A) 1639
B) 1847
C) 1750
D) 1829
E) 1689

2.                     10, 68, 222, 520, 1010, ?
A) 1950
B) 1840
C) 1740
D) 1010
E) None of these

3.                     168, 120, 80, 48, ?, 8 
A) 30
B) 12
C) 14
D) 24
E) 29

4.                     5, 7, 17, 31, 65, ?
A) 95
B) 115
C) 102
D) 127
E) 150

5.                     10, 15, 28, 49, 78, ? 
A) 122
B) 102
C) 117
D) 136
E) None of these

6.                     12, 24, 27, 54, 57, ? 
A) 116
B) 106
C) 114
D) 122
E) 146

7.                     3, 18, 33, 68, 95, ? 
A) 168
B) 159
C) 162
D) 150
E) 177

8.                     16, 41, 61, 85, ?, 145 
A) 124
B) 167
C) 119
D) 113
E) 185

9.                     25, 13, 21, 55, 196, ? 
A) 892.5
B) 942.5
C) 758.5
D) 828.5
E) 886.5

10.                 16, 43, 98, 209, ?, 879
A) 428
B) 432
C) 386
D) 422
E) 396

1.      B) 1847
Pattern: 
7*1 – 2, 5*2 – 3, 7*3 – 4, 17*4 – 5, 63*5 – 6, 309*6 – 7

2.      C) 1740
Pattern: 
2^3 + 2, 4^3 + 4, 6^3 + 6, 8^3 + 8, 10^3 + 10

3.      D) 24
Pattern: 
13² – 1, 11² – 1, 9² – 1, 7² – 1, 5² – 1, 3² – 1

4.      D) 127
Pattern: 
5*2 – 3, 7*2 + 3, 17*2 – 3, 31*2 + 3, 65*2 – 3

5.      E) None of these
Pattern: 
15-10 = 5, 28-15 = 13, 49-28 = 21, 78-49 = 29
13-5 = 8, 21-13 = 8, 29-21 = 8
So next number is 78+29+8 = 115

6.      C) 114
Pattern: 
12*2, 24+3, 27*2, 54+3, 57*2

7.      D) 150
Pattern: 
2² – 2/2, 4² + 4/2, 6² – 6/2, 8² + 8/2, 10² – 10/2, 12² + 12/2

8.      D) 113
Pattern: 
4^2, 4^2 + 5^2, 5^2 + 6^2, 6^2 + 7^2,….

9.      E) 886.5
Pattern: 
×0.5 + 0.5, ×1.5 + 1.5, ×2.5 + 2.5, ×3.5 + 3.5, ×4.5 + 4.5,

10. B) 432
Pattern: 
×2 + 11, ×2 + 12, ×2 + 13, ×2 + 14, ×2 + 15,