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1:
Find out the wrong number in the series.

7, 8, 18, 57, 228, 1165, 6996
Correct Answer : 228

Explanation:

7*1=8, 8*2+2=18, 18*3+3=57....

2: Find out the wrong number in the series.
1, 1, 2, 6, 24, 96, 720
Correct Answer : 96

Explanation:

Go on multiplying with 1, 2, 3, 4, 5, 6 to get the next number.

So, 96 is wrong.

3: Find out the wrong number in the series.
196, 169, 144, 121, 100, 80, 64
Correct Answer : 80

Explanation:

Numbers must be (14)2, (13)2, (12)2, (11)2, (10)2, (9)2, (8)2.

So, 80 is wrong.

4:

Find out the wrong number in the series.
445, 221, 109, 46, 25, 11, 4
Correct Answer : 46

Explanation:

Go on subtracting 3 and dividing the result by 2 to obtain the next number.

Clearly, 46 is wrong.

5:

Find out the wrong number in the series.
190, 166, 145, 128, 112, 100, 91
Correct Answer : 128

Explanation:

Go on subtracting 24, 21, 18, 15, 12, 9 from the numbers to get the next number.

190 - 24 = 166
166 - 21 = 145
145 - 18 = 127 [Here, 128 is placed instead of 127]
127 - 15 = 112
112 - 12 = 100 ... and so on.

Therefore, 128 is wrong.

6:

Find out the wrong number in the series.
19, 26, 33, 46, 59, 74, 91
Correct Answer : 33

Explanation:

Go on adding 7, 9, 11, 13, 15, 17 respectively to obtain the next number.

So, 33 is wrong. It must be 35

7: Find out the wrong number in the series.
1, 3, 10, 21, 64, 129, 356, 777
Correct Answer : 356

Explanation:

1 x 2 + 1, 3 x 3 + 1, 10 x 2 + 1, 21 x 3 + 1 and so on.

So, 356 is wrong.

8:

Find out the wrong number in the series.
6, 12, 48, 100, 384, 768, 3072
Correct Answer : 100

Explanation:

Each even term of the series is obtained by multiplying the previous term by 2.

2nd term = (1st term) x 2 = 6 x 2 = 12

4th term = (3rd term) x 2 = 48 x 2 = 96.

6th term = (5th term) x 2 = 384 x 2 =768.

 4th term should be 96 instead of 100.

9:

Find out the wrong number in the series.
40960, 10240, 2560, 640, 200, 40, 10
Correct Answer : 200

Explanation:

Go on dividing by 4 to get the next number.

So, 200 is wrong.

10: Find out the wrong number in the series.
3, 7, 15, 39, 63, 127, 255, 511
Correct Answer : 39

Explanation:

Go on multiplying 2 and adding 1 to get the next number.

So, 39 is wrong.

11:

Find out the wrong number in the series.
15, 16, 34, 105, 424, 2124, 12756
Correct Answer : 2124

Explanation:

2nd term = (1st term) x 1 + 1 = 15 x 1 + 1 = 16.

3rd term = (2nd term) x 2 + 2 = 16 x 2 + 2 = 34.

4th term = (3th term) x 3 + 3 = 34 x 3 + 3 = 105.

5th term = (4th term) x 4 + 4 = 105 x 4 + 4 = 424

6th term = (5th term) x 5 + 5 = 424 x 5 + 5 = 2125

 6th term should 2125 instead of 2124.

12:

Find out the wrong number in the series.
10, 26, 74, 218, 654, 1946, 5834
Correct Answer : 654

Explanation:

2nd term = (1st term) x 3 - 4 = 10 x 3 - 4 = 26.

3rd term = (2nd term) x 3 - 4 = 26 x 3 - 4 = 74.

4th term = (3th term) x 3 - 4 = 74 x 3 - 4 = 218.

5th term = (4th term) x 3 - 4 = 218 x 3 - 4 = 650.

 5th term must be 650 instead of 654.

13: Find out the wrong number in the series.
2880, 480, 92, 24, 8, 4, 4
Correct Answer : 92

Explanation:

Go on dividing by 6, 5, 4, 3, 2, 1 respectively to obtain the next number.

Clearly, 92 is wrong.

14: Find out the wrong number in the series.
3, 7, 15, 27, 63, 127, 255
Correct Answer : 27

Explanation:

Go on multiplying the number by 2 and adding 1 to it to get the next number.

So, 27 is wrong.