Missing Number – Railway Reasoning part – 4

Total Questions: 50

21. Find the missing number to complete the following sequence: [RRB NTPC 05/03/2021 (Evening)]

Correct Answer: (b) 3
Solution:

Logic :- 8 x 6 - 10 = 38, 9 x 4 - 15 = 21
Similarly, X x 4 - 6 = 6 ⇒ X = 12 ÷ 4 = 3

22. Find the missing number to complete the following sequence: [RRB NTPC 07/03/2021 (Morning)]

Correct Answer: (d) 16
Solution:

(7 -1 ) × 2 = 12
(9 - 5) × 2 = 8 , (14 - 6) × 2 = 16

23. Find the missing number to complete the following sequence: [RRB NTPC 07/03/2021 (Morning)]

Correct Answer: (b) 1
Solution:

(5 + 4 + 9) - (3 + 4) = 11
(3 + 4 + 6) - (2 +1 ) = 10
(2 + 3 +1 ) - (4 + 1) = 1

24. In the equations below, the function of the rectangle remains unchanged. Select the option that can replace the question mark(?) in the fourth equation. [RRB NTPC 07/03/2021 (Morning)]

Correct Answer: (b)
Solution:

25. The ★ represents a set of calculations that are common across all the given equations. Identify the calculations involved and solve the fourth equation on the same basis: [RRB NTPC 07/03/2021 (Morning)]

4 ★ 5 = 11
4 ★ 8 = 17
2 ★ 9 = 10
6 ★ 3 = ?

Correct Answer: (b) 10
Solution:

(4 × 5) ÷ 2 + 1 = 11
(4 × 8) ÷ 2 + 1 = 17
(2 × 9) ÷ 2 + 1 = 10
( 6 × 3) ÷ 2 + 1 = 10

26. Find the missing number to complete the following sequence: [RRB NTPC 07/03/2021 (Morning)]

Correct Answer: (b) 25
Solution:

Logic : Middle term = (sum of all numbers) ÷ 2
So, required number = (12 + 10 + 13 + 5) ÷ 2 = 20

27. Find the missing number to complete the following sequence: [RRB NTPC 08/03/2021 (Morning)]

Correct Answer: (b) 40
Solution:

28. In the equations below, the function of → remains unchanged. What does the question mark stand for in the fourth equation? [RRB NTPC 08/03/2021 (Morning)]

Correct Answer: (a) 41
Solution:

I. 9 → 3 = 32 ⇒ 9 × 3 + 5 = 32 ;
II. 6 → 7 = 47 ⇒ 6 × 7 + 5 = 47
III. 13 → 3 = 44 ⇒ 13 × 3 + 5 = 44 ;
IV. 12 → 3 = ? ⇒ 12 × 3 + 5 = 41 ;

29. Find the missing number to complete the following sequence: [ RRB NTPC 09/03/2021 (Morning)]

Correct Answer: (d) M
Solution:

6 + 2 + 4 = 12 → L
17 + 4 +1 = 22 → V 8 + 12 + 3 = 23 → W
Similarly, 1 + 5 + 7 = 13 → M

30. Find the missing number to complete the following sequence: [RRB NTPC 09/03/2021 (Evening)]

Correct Answer: (d) 10
Solution: