Explore topic-wise InterviewSolutions in .

This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.

1.

1, 4, 9, 16, 23, 25, 36

Answer» Each of the numbers except 23, is perfect square.
2.

10, 14, 16, 18, 21, 24, 26

Answer» Each of the numbers except 21 is an even number.
3.

835, 734, 642, 751, 853, 981, 532

Answer» In each number except 751, the difference of third and first digit is the middle one.
4.

1, 2, 6, 15, 31, 56, 91

Answer» 1, 1 + 12 = 2, 2 + 22 = 6, 6 + 32 = 15, 15 + 42 = 31, 31 + 52 = 56, 56 + 62 = 92 Last number of given series must be 92 not 91.
5.

7, 26, 63, 124, 215, 342, (....)

Answer» Numbers are (23 - 1), (33 - 1), (43 - 1), (53 - 1), (63 - 1), (73 - 1) etc. So, the next number is (83 - 1) = (512 - 1) = 511.
6.

3, 5, 7, 12, 17, 19

Answer» Each of the numbers is a prime number except 12.
7.

6, 13, 18, 25, 30, 37, 40

Answer» The differences between two successive terms from the beginning are 7, 5, 7, 5, 7, 5. So, 40 is wrong.
8.

3, 7, 15, 39, 63, 127, 255, 511

Answer» Go on multiplying 2 and adding 1 to get the next number. So, 39 is wrong.
9.

331, 482, 551, 263, 383, 362, 284

Answer» In each number except 383, the product of first and third digits is the middle one.
10.

3, 5, 11, 14, 17, 21

Answer» Each of the numbers except 14 is an odd number. The number '14' is the only EVEN number.
11.

8, 27, 64, 100, 125, 216, 343

Answer» The pattern is 23, 33, 43, 53, 63, 73. But, 100 is not a perfect cube.
12.

10, 25, 45, 54, 60, 75, 80

Answer» Each of the numbers except 54 is multiple of 5.
13.

396, 462, 572, 427, 671, 264

Answer» In each number except 427, the middle digit is the sum of other two.
14.

6, 9, 15, 21, 24, 28, 30

Answer» Each of the numbers except 28, is a multiple of 3.
15.

1, 4, 9, 16, 20, 36, 49

Answer» The pattern is 12, 22, 32, 42, 52, 62, 72. But, instead of 52, it is 20 which to be turned out.
16.

2, 5, 10, 17, 26, 37, 50, 64

Answer» (1*1)+1 , (2*2)+1 , (3*3)+1 , (4*4)+1 , (5*5)+1 , (6*6)+1 , (7*7)+1 , (8*8)+1 But, 64 is out of pattern.
17.

16, 25, 36, 72, 144, 196, 225

Answer» Each of the numbers except 72 is a perfect square.
18.

41, 43, 47, 53, 61, 71, 73, 81

Answer» Each of the numbers except 81 is a prime number.
19.

582, 605, 588, 611, 634, 617, 600

Answer» Alternatively 23 is added and 17 is subtracted from the terms. So, 634 is wrong.
20.

8, 13, 21, 32, 47, 63, 83

Answer» Go on adding 5, 8, 11, 14, 17, 20. So, the number 47 is wrong and must be replaced by 46.
21.

1, 8, 27, 64, 124, 216, 343

Answer» The numbers are 13, 23, 33, 43 etc. So, 124 is wrong; it must have been 53 i.e., 125.
22.

5, 10, 13, 26, 29, 58, 61, (....)

Answer» Numbers are alternatively multiplied by 2 and increased by 3. So, the missing number = 61 x 2 = 122.
23.

15, 31, 63, 127, 255, (....)

Answer» Each number is double the preceding one plus 1. So, the next number is (255 x 2) + 1 = 511.
24.

1, 8, 27, 64, 125, 216, (....)

Answer» Numbers are 13, 23, 33, 43, 53, 63. So, the missing number is 73 = 343.
25.

3, 7, 6, 5, 9, 3, 12, 1, 15, (....)

Answer» There are two series, beginning respectively with 3 and 7. In one 3 is added and in another 2 is subtracted. The next number is 1 - 2 = -1.
26.

11, 13, 17, 19, 23, 29, 31, 37, 41, (....)

Answer» Numbers are all primes. The next prime is 43.
27.

64, 71, 80, 91, 104, 119, 135, 155

Answer» Go on adding 7, 9, 11, 13, 15, 17, 19 respectively to obtain the next number. So, 135 is wrong.
28.

15, 16, 34, 105, 424, 2124, 12756

Answer» 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.
29.

10, 26, 74, 218, 654, 1946, 5834

Answer» 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.
30.

2880, 480, 92, 24, 8, 4, 4

Answer» Go on dividing by 6, 5, 4, 3, 2, 1 respectively to obtain the next number. Clearly, 92 is wrong.
31.

3, 7, 15, 27, 63, 127, 255

Answer» Go on multiplying the number by 2 and adding 1 to it to get the next number. So, 27 is wrong.
32.

19, 26, 33, 46, 59, 74, 91

Answer» Go on adding 7, 9, 11, 13, 15, 17 respectively to obtain the next number. So, 33 is wrong. It must be 35
33.

1, 3, 10, 21, 64, 129, 356, 777

Answer» A x 2 + 1, B x 3 + 1, C x 2 + 1, D x 3 + 1 and so on. So, 356 is wrong.
34.

6, 12, 48, 100, 384, 768, 3072

Answer» 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.
35.

40960, 10240, 2560, 640, 200, 40, 10

Answer» Go on dividing by 4 to get the next number. So, 200 is wrong.
36.

8, 24, 12, 36, 18, 54, (....)

Answer» Numbers are alternatively multiplied by 3 and divided by 2. So, the next number = 54 ÷ 2 = 27.
37.

2, 6, 12, 20, 30, 42, 56, (....)

Answer» The pattern is 1 x 2, 2 x 3, 3 x 4, 4 x 5, 5 x 6, 6 x 7, 7 x 8. So, the next number is 8 x 9 = 72.
38.

4, -8, 16, -32, 64, (....)

Answer» Each number is the proceeding number multiplied by -2. So, the required number is -128.
39.

7, 8, 18, 57, 228, 1165, 6996

Answer» Let the given numbers be A, B, C, D, E, F, G. Then, A, A x 1 + 1, B x 2 + 2, C x 3 + 3, D x 4 + 4, E x 5 + 5, F x 6 + 6 are the required numbers. Clearly, 228 is wrong.
40.

1, 1, 2, 6, 24, 96, 720

Answer» Go on multiplying with 1, 2, 3, 4, 5, 6 to get next number. So, 96 is wrong.
41.

196, 169, 144, 121, 100, 80, 64

Answer» Numbers must be (14)2, (13)2, (12)2, (11)2, (10)2, (9)2, (8)2. So, 80 is wrong.
42.

445, 221, 109, 46, 25, 11, 4

Answer» Go on subtracting 3 and dividing the result by 2 to obtain the next number. Clearly, 46 is wrong.
43.

190, 166, 145, 128, 112, 100, 91

Answer» 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.
44.

16, 33, 65, 131, 261, (....)

Answer» Each number is twice the preceding one with 1 added or subtracted alternatively. So, the next number is (2 x 261 + 1) = 523.
45.

10, 5, 13, 10, 16, 20, 19, (....)

Answer» There are two series (10, 13, 16, 19) and (5, 10, 20, 40), one increasing by 3 and the other multiplied by 2.
46.

1, 4, 9, 16, 25, 36, 49, (....)

Answer» Numbers are 12, 22, 32, 42, 52, 62, 72. So, the next number is 82 = 64.
47.

2, 4, 12, 48, 240, (....)

Answer» Go on multiplying the given numbers by 2, 3, 4, 5, 6. So, the correct next number is 1440.
48.

8, 7, 11, 12, 14, 17, 17, 22, (....)

Answer» There are two series (8, 11, 14, 17, 20) and (7, 12, 17, 22) increasing by 3 and 5 respectively.
49.

46080, 3840, 384, 48, 24, 2, 1

Answer» The terms are successively divided by 12, 10, 8, 6, ...etc. So, 24 is wrong, it should be 8 (48/6 = 8).
50.

36, 54, 18, 27, 9, 18.5, 4.5

Answer» The terms are alternatively multiplied by 1.5 and divided by 3. However, 18.5 does not satisfy it.