Mathematical Operations – Railway Reasoning (part – 2)

Total Questions: 50

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

69 - 23 + 15 ÷ 11 × 12 = - 114

Correct Answer: (a) - and ÷
Solution:

In this type of question, we will check by putting options one by one and doing so option (a) gets satisfied
69 - 23 + 15 ÷ 11 × 12 = - 114
After changed mathematical symbol, we get
L.H.S = 69 ÷ 23 + 15 - 11 × 12
= 3 + 15 - 11 × 12 = 3 + 15 - 132
= 18 - 132 = -114
L.H.S = R.H.S

22. If ‘+’ means ‘-’, ‘-’ means ‘×’, ‘×’ means ‘÷’, ‘÷’ means ‘+’, what will come in place of the question mark (?) in the following equation? [Group - D 15/09/2022 (Evening)]

21 + 7 - 3 ÷ 20 × 5 = ?

Correct Answer: (a) 4
Solution:

Given expression:
21 + 7 - 3 ÷ 20 × 5
After changed mathematical symbol
21 - 7 × 3 + 20 ÷ 5 = 21 - 21 + 4 = 4

23. If ‘×’ and ‘÷’ are interchanged, what will be the value of the given expression? [Group - D 15/09/2022 (Evening)]

13 - 7 + 8 ÷ 2 × 10

Correct Answer: (a) 85
Solution:

Given: 13 - 7 + 8 ÷ 2 × 10
As per given instruction after changing  mathematical symbol
13 × 7 + 8 ÷ 2 - 10 = 91 + 4 - 10 = 85

24. If ‘+’ means ‘-’, ‘-’ means ‘×’, ‘×’ means ‘÷’ and ‘÷’ means ‘+’, what will come in place of the question mark (?) in the following equation? [Group - D 16/09/2022 (Morning)]

88 × 22 - 15 ÷ 40 + 19 = ?

Correct Answer: (c) 81
Solution:

Given expression:
88 × 22 - 15 ÷ 40 + 19
After changed mathematical symbol
88 ÷ 22 × 15 + 40 - 19
= 4 × 15 + 40 - 19 = 60 + 40 - 19 = 81

25. Which two number should be interchanged to make the following equation correct ? [Group - D 16/09/2022 (Afternoon)]

12 + 7 - (8 ÷ 4 - 5) × 11 = 54

Correct Answer: (a) 12 and 11
Solution:

Given expression :
12 + 7 - (8 ÷ 4 - 5) × 11 = 54
Check each option one by one , option a satisfied the equation.
11 + 7 - (8 ÷ 4 - 5) × 12
= 11 + 7 + 3 × 12 = 18 + 36 = 54

26. If ‘+’ means ' ', ‘-' means ' ', ' ÷ + × 'means ' 'and ` `, means' ', then, what − ÷ × will be the value of the following expression? [Group - D 16/09/2022 (Evening)]

[{(48 × 28) ÷ (5 ÷ 3)) + (3 - 4)]

Correct Answer: (d) 5
Solution:

Given :
[{(48 × 28) - (5 ÷ 3)} + (3 - 4)]
As per given instruction after changing mathematical symbol,
= [(48 - 28) + (5 × 3) ÷ (3 + 4)]
= [{20 + 15} ÷ 7] = [35 ÷ 7] = 5

27. If ‘+’ means ‘-’, ‘-’ means ‘x’, ‘x’ means ‘÷’, ‘÷’ means ‘+’, what will come in place of the question mark(?) in the following equation ? [Group - D 17/09/2022 (Morning)]

17 ÷ 3 - 2 + 12 × 4 = ?

Correct Answer: (c) 20
Solution:

17 ÷ 3 - 2 + 12 × 4 = ?
As per question, symbols are interchanged.
17 + 3 × 2 - 12 ÷ 4 ⇒ 17 + 6 - 3 = 20

28. If ‘+’ means ‘÷’, ‘-’ means ‘+’, ‘÷’ means ‘x’, ‘x’ means ‘-’, what will come in place of question mark (?) in the following equation ? [Group - D 17/09/2022 (Morning)]

2 - 4 × 25 + 13 ÷ 2 = ?

Correct Answer: (a) -0.5
Solution:

2 - 4 × 25 + 13 ÷ 2 = ?
As per question,
2 ÷ 4 + 25 - 13 × 2
⇒ 0.5 + 25 - 26 = -0.5

29. If ‘+’ means ‘÷’, ‘-’ means ‘x’, ‘x’ means ‘÷’, and ‘÷’ means ‘+’ what will come in place of the question mark (?) in the following equation ? [Group - D 17/09/2022 (Afternoon)]

44 × 11 - 25 ÷ 20 + 80 = ?

Correct Answer: (a) 40
Solution:

44 × 11 - 25 ÷ 20 + 80 = ?
According to questions,
44 ÷ 11 × 25 + 20 - 80
= 4 × 25 + 20 - 80 = 120 - 80 = 40

30. What will come in place of the question mark (?) in the following equation, if ‘x’ is replaced with ‘÷’ and ‘-’ is replaced with ‘x’ [Group - D 18/09/2022 (Morning)]

14 × 2 + 5 - 56 ÷ 8 = ?

Correct Answer: (d) 42
Solution:

Given : 14 × 2 + 5 - 56 ÷ 8
As per instructions after changing the sign
14 ÷ 2 + 5 × 56 ÷ 8
= 7 + 5 × 7 = 7 + 35 = 42