Missing Number – Railway Reasoning part – 2

Total Questions: 50

21. Find the missing number to complete the following sequence: [RRB NTPC 23/01/2021 (Evening)]

Correct Answer: (b) 1
Solution:

2 × 3 × 4 = 24
9 × 8 × 7 = 504
5 × 1 × 6 = 30

22. Find the missing number to complete the following sequence: [RRB NTPC 23/01/2021 (Evening)]

Correct Answer: (c) 454
Solution:

(1² + 3² + 5² + 7²) × 2 = (1 + 9 + 25 + 49) × 2 = 84 × 2 = 168
(2² + 4² + 6² + 8²) × 2 = (4 + 16 + 36 + 64) × 2 = 120 × 2 = 240
(0² + 9² + 5² + 11²) × 2 = (0 + 81 + 25 + 121) × 2 = 227 × 2 = 454

23. Of the three given equations, the first two are solved on the basis of a certain system. Find the correct answer for the unsolved third equation on the same basis. [RRB NTPC 25/01/2021 (Morning)]

Correct Answer: (b) 59
Solution:

24. Find the missing number to complete the following sequence: [RRB NTPC 25/01/2021 (Morning)]

Correct Answer: (d) 13
Solution:

For figure 1 → (12 + 10 ) – ( 5 +7 ) =10
For figure 2 → (11 +16) – ( 8 + 4 ) = 15
For figure 3 → ( 15 + 9 ) – ( 5 + 6 ) = 13

25. Find the missing number to complete the following sequence: [RRB NTPC 27/01/2021 (Morning)]

Correct Answer: (d) 720
Solution:

2 × 3 × 4 = 24
5 × 6 × 7 = 210
8 × 9 × 10 = 720

26. Find the missing number to complete the following sequence: [RRB NTPC 27/01/2021 (Morning)]

Correct Answer: (a) 145
Solution:

4 × 5 × 2 + 1 = 41
6 × 7 × 2 + 1 = 85
8 × 9 × 2 + 1 = 145

27. Find the missing number to complete the following sequence: [RRB NTPC 27/01/2021 (Morning)]

Correct Answer: (a) 11
Solution:

Columnwise,
(First number × second number) + first number
2 × 3 = 6 + 2 = 8
13 × 9 = 117 + 9 = 126
So 16 × 11 = 176 + 16 = 192

28. Find the missing number to complete the following sequence: [RRB NTPC 27/01/2021 (Evening)]

Correct Answer: (b) 8
Solution:

6 × 4 + 5 = 29
8 × 5 + 8 = 48

29. Find the missing number to complete the following sequence: [RRB NTPC 27/01/2021 (Morning)]

Correct Answer: (d) 145
Solution:

Here the pattern is :
For the first diagram :
4 × 4 + 5 × 5 = 41
For the second diagram :
6 × 6 + 7 × 7 = 85
Similarly :
For the third diagram :
8 × 8 + 9 × 9 = 145

30. Find the missing number to complete the following sequence: [RRB NTPC 27/01/2021 (Evening)]

Correct Answer: (a) 13
Solution:

3 × 6 = 18
4 × 5 = 20
6 × 10 = 60
8 × 13 = 104
18 + 20 + 60 + 104 = 202