1. Find out the wrong term: 325, 259, 202, 160, 127, 105, 94
a) 94
b) 127
c) 202
d) 259
Explanation: The correct pattern is - 66, - 55, - 44, - 33, - 22, - 11.
So, 202 is wrong and must be replaced by (259 - 55) i.e., 204.
2. Find out the wrong term: 3, 4, 10, 32, 136, 685, 4116
a) 10
b) 32
c) 136
d) 4116
Explanation: The correct pattern is × 1 + 1, × 2 + 2, × 3 + 3, × 4 + 4, ..........
So, 32 is wrong and must be replaced by (10 × 3 + 3) i.e., 33.
3. Find out the wrong term: 380, 188, 92, 48, 20, 8, 2
a) 8
b) 20
c) 48
d) 188
Explanation: The correct pattern is - 192, - 96, - 48, - 24, - 12, - 6.
So, 48 is wrong and must be replaced by (92 - 48) i.e., 44.
4. Find out the wrong term: 2, 6, 24, 96, 285, 568, 567
a) 6
b) 24
c) 285
d) 567
Explanation: The correct pattern is ×6 -6, ×5 -5, ×4 -4, ×3 -3, . . . . .
So, 24 is wrong and must be replaced by (6 × 5 - 5) i.e., 25
5. Find out the wrong term: 89, 78, 86, 80, 85, 82, 83
a) 83
b) 82
c) 86
d) 78
Explanation: The correct pattern is - 11, + 9, - 7, + 5, - 3 + 1.
So, 86 is wrong and must be replaced by (78 + 9) i.e., 87.
6. In a given series one term is wrong or missing term: 1, 2, 5, 10, 17, 28
a) 30
b) 28
c) 27
d) 17
Explanation: The correct sequence is + 1, + 3, + 5, + 7, + 9.
So, 28 is wrong and must be replaced by (17 + 9) i.e., 26.
7. In a given series one term is wrong or missing term: 0, 3, 8, 15, 24, 33
a) 8
b) 15
c) 26
d) 33
Explanation: The correct pattern is + 3, + 5, + 7, + 9, + 11.
So, 33 is wrong and must be replaced by (24 + 11) i.e., 35.
8. In a given series one term is wrong or missing term: 2, 3, 5, 8, 13, 34
a) 21
b) 25
c) 29
d) 34
Explanation: Clearly, each term of the series is the sum of the preceding two terms.
Now, 8 + 13 = 21 and 13 + 21 = 34.
So, the term 21 is missing.
9. In a given series one term is wrong or missing term: 1, 5, 11, 19, 29, 55
a) 55
b) 41
c) 29
d) 19
Explanation: The correct sequence is + 4, + 6, + 8, + 10, ............
So, next term after 29 = 29 + 12 = 41.
The term after 41 will then be (41 + 14) i.e., 55.
∴ 41 is missing.
10. Find the missing term : 4, 6, 10, 16, 24, ?
a) 40
b) 34
c) 30
d) 28
Explanation: 1st term : 4
2nd term : 4 + 2 = 6
3rd term : 6 + 4 = 10
4th term : 10 + 6 = 16
5th term : 16 + 8 = 24
So,
6th term : 24 + 10 = 34