Mathematical Operations – Railway Reasoning (part – 2)

Total Questions: 50

11. If ‘+’ means ‘-’, ‘-’ means ‘×’, ‘×’ means ‘÷’, and ‘÷’ means ‘+’, what will come in place of the question mark (?) in the following equation? [Group - D 12/09/2022 (Afternoon)]

18 × 3 - 15 ÷ 10 + 20 = ?

Correct Answer: (b) 6
Solution:

18 × 3 - 15 ÷ 10 + 20 = ?
After changing the signs as per given instructions we get,
18 ÷ 3 × 15 + 10 - 20 = 90 + 10 - 20 = 80

12. If ‘+’ means ‘-’, ‘-’ means ‘×’, ‘×’ means ‘÷’, and ‘÷’ means ‘+’, what will come in place of the question mark (?) in the following equation? [Group - D 12/09/2022 (Evening)]

18 ÷ (18 - 2) × 9 + 16 = ?

Correct Answer: (b) 6
Solution:

Given, 18 ÷ (18 - 2) × 9 + 16
By changing sign as per given question we get, 18 + (18 × 2) ÷ 9 - 16 = 6

13. If ‘+’ means ‘-’, ‘-’ means ‘×’, ‘×’ means ‘÷’, and ‘÷’ means ‘+’, what will come in place of the question mark (?) in the following equation? [Group - D 13/09/2022 (Morning)]

12 × 3 - 25 ÷ 25 + 25 = ?

Correct Answer: (c) 100
Solution:

12 × 3 - 25 ÷ 25 + 25 = ?
As per given instructions after changing the signs we get,
12 ÷ 3 × 25 + 25 - 25
= 100 + 25 - 25 = 100

14. What will come in the place of the question mark (?) in the following equation, if ‘+’ and ‘-’ are interchanged and also ‘×’ and ‘÷’ are interchanged? 24 × 6 ÷ 5 - 3 + 2 = ? [Group - D 13/09/2022 (Morning)]

Correct Answer: (a) 21
Solution:

24 × 6 ÷ 5 - 3 + 2 =?
After interchanging the signs as per given instructions we get,
24 ÷ 6 × 5 + 3 - 2 = 20 + 3 - 2 = 21

15. Which two signs should be interchanged to make the following equation correct? [Group - D 13/09/2022 (Evening)]

28 ÷ 4 - 12 × 5 + 11 = 56

Correct Answer: (b) + and -
Solution:

In this type of question, we will check by putting options one by one and doing so option (b) gets satisfy.
Given question: 28 ÷ 4 - 12 × 5 + 11 = 56
after interchanged mathematical symbol
+ and –
28 ÷ 4 + 12 × 5 - 11 = 56
⇒ 7 + 12 × 5 - 11 = 56 ⇒ 7 + 60 - 11 = 56
⇒ 67 - 11 = 56 ⇒ 56 = 56 (satisfy)

16. What will come in the place of the question mark (?) in the following equation, if ‘+’ and ‘-’ are interchanged and also ‘×’ and ‘÷’ are interchanged? [Group - D 14/09/2022 (Morning)]

12 × 6 ÷ 9 - 3 + 2 = ?

Correct Answer: (d) 19
Solution:

Given Equation:
12 × 6 ÷ 9 - 3 + 2
After changing mathematical symbol
12 ÷ 6 × 9 + 3 - 2
⇒ 18 + 3 - 2 ⇒ 21 - 2 = 19

17. If ‘+’ means ‘×’, ‘×’ means ‘÷’, ‘÷’ means ‘-’, ‘-’ means ‘+’, then what will be the value of the given expression? [Group - D 14/09/2022 (Afternoon)]

215 × 5 ÷ 4 - 18 × 3

Correct Answer: (d) 45
Solution:

Given expression:
215 × 5 ÷ 4 - 18 × 3
After changed mathematical symbol,
⇒ 215 ÷ 5 - 4 + 18 ÷ 3 ⇒ 43 - 4 + 6
⇒ 49 - 4 = 45

18. If ‘+’ means ‘×’, ‘×’ means ‘÷’, ‘÷’ means ‘-’, and ‘-’ means ‘+’, then what will be the value of the given expression? [Group - D 14/09/2022 (Afternoon)]

87 × 3 - 8 + 5 ÷ 10

Correct Answer: (d) 59
Solution:

Given expression:
87 × 3 - 8 + 5 ÷ 10
After changed the mathematical symbol,
⇒ 87 ÷ 3 + 8 × 5 - 10 ⇒ 29 + 8 × 5 - 10
⇒ 29 + 40 - 10 ⇒ 69 - 10 = 59

19. If × stand for -, ÷ stand for +, + stand for ÷ and - stands for ×, what will come in place of the question (?) in the following equation? [Group - D 14/09/2022 (Afternoon)]

24 ÷ 30 - 9 + 15 × 18 = ?

Correct Answer: (c) 24
Solution:

Given expression:
24 ÷ 30 - 9 + 15 ×18
After changing mathematical symbol,
24 + 30 × 9 ÷ 15 - 18 ⇒ 24 + 18 - 18 = 24

20. What will come in the place in place of ‘?’ in the following equation, if ‘+’ and ‘-’ are interchanged and also ‘×’ and ‘÷’ are interchanged ? [Group - D 15/09/2022 (Morning)]

45 × 15 ÷ 40 - 30 + 5 = ?

Correct Answer: (a) 145
Solution:

Given equation:
45 × 15 ÷ 40 - 30 + 5 = ?
Equation after exchange of mathematical symbol
45 ÷ 15 × 40 + 30 - 5
⇒ 3 × 40 + 30 - 5 ⇒ 120 + 30 - 5
⇒ 150 - 5 = 145