Number series

1)2, 7, 14, 23, ?, 47 

A.    31

B.    28

C.    34

D.    38

Answer : C.

The given sequence is +5, +7, +9, —— 
ie. 2+ 5 = 7, 7 + 7 = 14, 14 + 9 = 23
Missing Number = 23 + 11 = 34.

2) 4, 6, 12, 14, 28, 30, ? 

 A.    32

 B.    64

 C.    62

 D.    60

Answer : D.

The given sequence is a combination of two series 4, 12, 28, .... and 6, 14, 30, .... The pattern is +8, +16, +32. So, the missing number = (28 + 32) = 60

3) 4, 9, 13, 22, 35, ? 

A.    57

 B.    70

 C.    63

 D.    75

Answer : A

Sum of two consecutive numbers of the series gives the next number.

4) 11, 13, 17, 19, 23, 29, 31, 37, 41, ? 

A.    43

B.    47

C.    51

 D.    53

Answer : A.

The series consists of prime numbers.

5) 15, 31, 63, 127, 255, ? 

 A.    513

 B.    511

C.    523

 D.    517

Answer : B.

Each number is double of the preceding one plus 1.