Mathematical Operations – Railway Reasoning (part – 2)

Total Questions: 50

31. If ‘+’ means ‘-’, ‘-’ means ‘x’, ‘x’ means ‘÷’, ‘÷’ means ‘+’, what will come in place of the question mark (?) [Group - D 18/09/2022 (Morning)]

15 - 4 ÷ 2 + 10 × 2 = ?

Correct Answer: (d) 57
Solution:

Given expression :
15 - 4 ÷ 2 + 10 × 2
After interchanging the symbols,
15 × 4 + 2 - 10 ÷ 2 = 60 + 2 - 5 = 57

32. What will come in the place of ‘?’ in the following equation, if ‘+’ and ‘-’ are interchanged and also ‘x’ and ‘÷’ are interchanged? [Group - D 18/09/2022 (Afternoon)]

15 ÷ 27 × 3 + 36 - 12 = ?

Correct Answer: (c) 111
Solution:

15 ÷ 27 × 3 + 36 - 12
After interchanging the mathematical signs
15 × 27 ÷ 3 - 36 + 12
= 15 × 9 - 36 + 12 = 135 - 24 = 111

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

490 × 7 + 2 - 8 ÷ 6

Correct Answer: (c) 142
Solution:

490 × 7 + 2 - 8 ÷ 6
After interchanging the symbols,
490 ÷ 7 × 2 + 8 - 6
= 70 × 2 + 8 - 6 = 140 + 8 - 6 = 142

34. What will come in the place of question mark (?) in the following equation, if ‘+’ and ‘-’ are interchanged and also ‘x’ and ‘÷’ are interchanged? [Group - D 19/09/2022 (Evening)]

160 × 8 + 12 - 6 ÷ 180 × 6 - 4 = ?

Correct Answer: (a) 192
Solution:

160 × 8 + 12 - 6 ÷ 180 × 6 - 4 = ?
According to question,
160 ÷ 8 - 12 + 6 × 180 ÷ 6 + 4
⇒ 20 - 12 + 6 × 30 + 4
⇒ 20 - 12 + 180 + 4 = 192

35. If ‘÷’ means ‘-’, ‘-’ means ‘x’, ‘x’ means ‘+’, ‘+’ means ‘÷’, what will come in place of the question mark (?) in the following equation? [Group - D 19/09/2022 (Evening)]

38 ÷ 10 × 5 - 7 + 10 × 2 - ?

Correct Answer: (c) 47 
Solution:

38 ÷ 10 × 5 - 7 + 10 × 2 = ?
According to question,
38 + 10 ÷ 5 × 7 - 10 ÷ 2
⇒ 38 + 2 × 7 - 5 ⇒ 38 + 14 - 5 = 47

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

120 × 4 ÷ 2 - 8 + 10 = ?

Correct Answer: (a) 58
Solution:

Given expression :
120 × 4 ÷ 2 - 8 + 10
After interchanging the symbols,
120 ÷ 4 × 2 + 8 - 10
⇒ 30 × 2 + 8 - 10 ⇒ 60 + 8 - 10 ⇒ 58

37. Which two mathematical operators should be interchanged to make the given equation correct ? [Group - D 20/09/2022 (Morning)]

18 × 6 + 12 - 7 ÷ 2 = 1

Correct Answer: (b) × and ÷
Solution:

Given expression :
18 × 6 + 12 - 7 ÷ 2 = 1
By hit and trial method check option one by one, option b satisfies this expression.
18 ÷ 6 + 12 - 7 × 2 = 1
⇒ 3 + 12 - 14 = 1 ⇒ 15 - 14 = 1 ⇒ 1 = 1

38. If ‘+’ means ‘-’, ‘-’ means ‘x’, ‘x’ means ‘÷’, ‘÷’ means ‘+’ what will come in place of the question mark (?) in the following equation? [Group - D 20/09/2022 (Afternoon)]

30 - 2 ÷ 4 + 12 × 6 = ?

Correct Answer: (b) 62
Solution:

Given expression :
30 - 2 ÷ 4 + 12 × 6
After interchanging the symbols,
30 × 2 + 4 - 12 ÷ 6 = 60 + 4 - 2 = 62

39. 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 20/09/2022 (Afternoon)]

4 × 2 ÷ 6 - 3 + 1 = ?

Correct Answer: (c) 14 
Solution:

Given :
4 × 2 ÷ 6 - 3 + 1
After interchanging the symbols,
4 ÷ 2 × 6 + 3 - 1
= 2 × 6 + 3 - 1 = 12 + 3 - 1 = 14

40. 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 20/09/2022 (Evening)]

16 ÷ 3 - 12 × 4 ÷ 18 × 3 - 7 = ?

Correct Answer: (b) 73
Solution:

Given expression :
16 ÷ 3 - 12 × 4 ÷ 18 × 3 - 7
After changing the symbols ,
16 × 3 + 12 ÷ 4 × 18 ÷ 3 + 7
= 48 + 3 × 6 + 7 = 48 + 18 + 7 = 73