Find the wrong number in the given number series? 10, 21, 54, 109, 189

Correct Answer: 289

Explanation:

Here the given number series is 270, 261, 279, 252, 289, 243

270 - 9 = 261

261 + 18 = 279

279 - 27 = 252

252 + 36 = 288 (not equals to 289)

288 - 45 = 243

 

Hence, the odd number in the given number series is 289.

Correct Answer: 81

Explanation:

The series follows the following pattern.

 

4

 

16 =  4 2

 

37 =  1 2 + 6 2

 

58 =  3 2 + 7 2

 

81  ? 5 2 + 8 2.

 

Here every number is based on the digits of previous number. Hence, 81 is the wrong number in the given series.

Correct Answer: 4-15-24

Explanation:

In each term second two numbers are multiples of the first number. But in 4-15-24 15 is not multiple of 4.

Correct Answer: 392

Explanation:

The sum of the digits in 708, 618 and 816 is 15, but not in 392.

Correct Answer: 72

Explanation:

With close observation, you will note that each number in the list is in the middle of two prime numbers. Thus:

4 is in the middle of 3 and 5, 6 is in the middle of 5 and 7, 12 is in the middle of 11 and 13, 18 is in the middle of 17 and 19, 30 is in the middle of 29 and 31. 42 is in the middle of 41 and 43, 60 is in the middle of 59 and 61.

Therefore, the next number would be the one that is in the middle of the next two prime numbers, which is 72 (which is in the middle of 71 and 73).

Correct Answer: 38

Explanation:

The given series is 15, 19, 27, 38, 55, 75

15

15 + 4 = 19

19 + 8 = 27

27 + 12 = 39

39 + 16 = 55

55 + 20 = 75

 

Hence, the odd number in the given series is 38.

Correct Answer: 4096

Explanation:

Here given series follows a pattern that

0.25, 8, 128, 1024, ?

0.25 x 32 = 8

8 x 16 = 128

128 x 8 = 1024

1024 x 4 = 4096

Correct Answer: 67

Explanation:

Here the given series 7, 11, 19, 35, ?

follows a pattern that (x 2 - 3) i.e,

7

7 x 2 - 3 = 11

11 x 2 - 3 = 19

19 x 2 - 3 = 35

35 x 2 - 3 = 67

67 x 2 - 3 = 131

 

Hence the next number in the given number series is 67.

Correct Answer: 449

Explanation:

Given number series is 5  19  49  101  181  295 ?

Here the series follows pattern that

5   19   49   101   181   295  ?

  14   30   52    80     114   (difference)

      16  22   28     34 (difference)

         6     6     6  (Common difference)

 

Therefore, the missing number in the series is ? = 295 + 115 + 34 + 6 = 449.

Correct Answer: 88

Explanation:

The given number series 2676, 445, ?, 21,6, 2, 1 follows a pattern that,

From right side,

1

1 x 1 + 1 = 2

2 x 2 + 2 = 6

6 x 3 + 3 = 21

21 x 4 + 4 = 88

88 x 5 + 5 = 445

445 x 6 + 6 = 2676

 

Hence the missing number in the given number series is 88.