# Missing Numbers Quiz Set 028

### Question 1

One term in the number series is wrong. Find out the wrong term.

10, 13, 26, 37, 51, 85, 154

A

10

B

26

C

51

D

154

Soln.
Ans: c

10 + 16 = 26, then 13 + 24 = 37, then 26[the first term] + 32 = 58 and then 85 = 37[the second term] + 48, hence, the wrong term is 51.

### Question 2

In the following number series, one of the numbers does not fit into the series. Find the wrong number.

2, 6, 24, 96, 285, 568, 567

A

6

B

24

C

96

D

285

Soln.
Ans: b

Number 24 is wrong and should be replaced by 25. The series should be 2 X 6 - 6 = 6, then 6 X 5 - 5 = 25, 25 X 4 - 4 = 96, then 96 X 3 - 3 = 285, then 285 X 2 - 2 = 568, then 568 X 1 - 1 = 567.

### Question 3

In the following number series, one of the numbers does not fit into the series. Find the wrong number.

225, 289, 338, 374, 397, 415, 424

A

415

B

289

C

338

D

397

Soln.
Ans: d

Number 397 is wrong and should be replaced by 399. The series is 225 + 8² gives 289, then 289 + 7² gives 338, then 338 + 6² gives 374, then 374 + 5² should give 399 not 397.

### Question 4

Directions: Find the missing number in the following series.

77, 78, 77, 81, 73, ?, 55

A

69

B

71

C

82

D

89

Soln.
Ans: c

Series increases and decreases alternatively with a difference of +1², −1³, +2², −2³, +3², −3³, i.e., +1, −1, +4, −8, +9, −27. The missing number is 73 + 3² = 82.

### Question 5

3, (?), 15, 31, 63, 127.

A

7.

B

5.

C

10.

D

12.

Soln.
Ans: a

3 (3 x 2 + 1), 7 (7 x 2 + 1), 15 (15 x 2 + 1), 31 (31 x 2 + 1), 63 (63 x 2 + 1), 127. 