1. Find the missing term: 2, 12, 36, 80, 150, ?
a) 194
b) 210
c) 252
d) 258
Explanation: The given series is a triangular pattern series.
So, we have
2 12 36 80 150 ?
10 24 44 70
14 20 26
6 6
So, missing term
= 150 + (70 + 26 + 6)
= 150 + 102
= 252
2. Find the missing term: 625, 5, 125, 25, 25, ?, 5
a) 5
b) 25
c) 125
d) 625
Explanation: The given sequence is a combination of two series:
I. 625, 125, 25, 5 and
II. 5, 25, ?
The pattern is ÷ 5, while that in II is × 5.
So, missing term = 25 × 5 = 125
3. Find the missing term: 2, 9, 28, ?, 126, 126, 217, 344
a) 50
b) 65
c) 70
d) 82
Explanation: The given series is a triangular pattern series.
So, we have
Series I : 2 9 28 ?
126 217 344
Series II : 7 19 ?
? 91 127
Series III : 12 ? ?
? 36
Clearly, to form a pattern, the missing terms in Series III must be 18, 24, 30
So, missing term
= 127 + (61 + 24 + 6)
= 127 + 91
= 218
4. Find the missing term: 11, 10, ?, 100, 1001, 1000, 10001
a) 101
b) 110
c) 111
d) None of these
Explanation: The pattern is - 1, × 10 + 1, - 1, × 10 + 1, - 1, × 10 +1, ....
So, the missing term = 10 × 10 + 1 = 101
5. Which of the following will not be a number of the series 1, 8, 27, 64, 125, ....?
a) 256
b) 512
c) 729
d) 1000
Explanation: The given series consists of cubes of natural numbers only. 256 is not the cube of any natural number.
6. Find out the wrong term: 46080, 3840, 384, 48, 24, 2, 1
a) 384
b) 48
c) 24
d) 2
Explanation: The correct pattern is ÷ 12, ÷ 10, ÷ 8, ÷ 6,.........
So, 24 is wrong and must be replaced by (48 ÷ 6) i.e., 8.
7. Find out the wrong term: 25, 36, 49, 81, 121, 169, 225
a) 36
b) 49
c) 169
d) 225
Explanation: The correct sequence is 52 , 72 , 92 , 112 , 132 , 152.
So, 36 is wrong.
8. Find out the wrong term: 5, 10, 40, 80, 320, 550, 2560
a) 80
b) 320
c) 550
d) 2560
Explanation: The correct pattern is ×2, ×4, ×2, ×4 . . . . . .
So, 550 is wrong and must be replaced by (320 × 2) i.e., 640
9. Find out the wrong term: 2, 5, 10, 17, 26, 37, 50, 64
a) 17
b) 26
c) 37
d) 64
Explanation: The term of the series are (12 + 1)(22 + 1)(32 + 1)(42 + 1)(52 + 1)(62 + 1)(72 + 1),..............
So, 64 is wrong and must be replaced by (82 + 1) i.e., 65
10. Find out the wrong term: 3, 7, 15, 39, 63, 127, 255, 511
a) 15
b) 39
c) 63
d) 127
Explanation: The correct pattern is × 2 + 1.
So, 39 is wrong and must be replaced by (15 × 2 + 1) i.e., 31.