Mathematical Operations – Railway Reasoning (part – 2)

Total Questions: 50

1. If ‘+’ means ‘÷’, ‘-’ means ‘+’, ‘×’ means ‘-’, and ‘÷’ means ‘×’, then what will be the value of the following expression? [Group - D 06/09/2022 (Morning)]

[{(19 × 12) - (2 ÷ 4)} + (2 - 3)] ÷ 2

Correct Answer: (d) 6
Solution:

Given:
[{(19 × 12) - (2 ÷ 4)} + (2 - 3)] ÷ 2
By interchanging signs according to the question we get,
[{(19 - 12) + (2 × 4)} ÷ (2 + 3)] × 2
[15 ÷ 5] × 2 = 6

2. If, × means ‘divide’; — means ‘add’; ÷ means ‘subtract’; And + means ‘multiply’, So what is the value of the expression [Group - D 06/09/2022 (Morning)]

17 ÷ 17 + 21 × 7 - 13 ?

Correct Answer: (d) -21
Solution:

Given: 17 ÷ 17 + 21 × 7 - 13
By interchanging signs according to the question we get ,
17 - 17 × 21 ÷ 7 + 13 = -21(ans)

3. Which of the following two numbers should be interchanged to make the given equation correct? [Group - D 08/09/2022 (Afternoon)]

35 × 13 ÷ 7 + 9 - 14 = 44

Correct Answer: (d) 9 and 13
Solution:

35 × 13 ÷ 7 + 9 - 14 = 44
By using Hit and Trial method to one by one we get,
35 × 9 ÷ 7 + 13 - 14 = 45 + 13 - 14
⇒ 44 = R.H.S.

4. What will come in place of the question mark (?) in the following equation, if ‘+’ and ‘-’ are interchanged and also ‘×’ and ‘÷’ are interchanged? [Group - D 08/09/2022 (Evening)]

10 ÷ 5 + 144 ÷ 12 + 13 - 45 × 9 + 12 = ?

Correct Answer: (a) 18
Solution:

Given,
10 ÷ 5 + 144 ÷ 12 + 13 - 45 × 9 + 12
By changing sign as per question we get,
10 × 5 - 144 ÷ 12 - 13 + 45 ÷ 9 - 12 ⇒ 18

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

13 ÷ 7 + 132 × 11 + 23 - 512 × 2 + 122 = ?

Correct Answer: (a)190
Solution:

Given,
13 ÷ 7 + 132 × 11 + 23 - 512 × 2 + 122
By changing sign as per question we get,
13 × 7 - 132 ÷ 11 - 23 + 512 ÷ 2 - 122
⇒ 91 - 12 - 23 + 256 - 122 = 190

6. If A means 'addition', B means 'multiplication', C means 'subtraction' and D means 'division', then 40 D 2 A 3 B 8 C 5 = ? [Group - D 09/09/2022 (Afternoon)]

Correct Answer: (c) 39
Solution:

40 D 2 A 3 B 8 C 5 =? (given)
As per given instructions arranging the signs we get,
40 ÷ 2 + 3 × 8 - 5 = 20 + 24 - 5 = 39

7. Which of the following interchanges of numbers would make the given equation correct? [Group - D 09/09/2022 (Afternoon)]

10 ÷ 6 × 4 + 14 - 24 = 30

Correct Answer: (c) 10, 30
Solution:

10 ÷ 6 × 4 + 14 - 24 = 30
By using Hit and Trial method (by choosing option one by one) we get,
After interchanging 10, 30 we get,
30 ÷ 6 × 4 + 14 - 24 = 10
= 20 + 14 - 24 ⇒ 10 = R.H.S.

8. What will be the value of the given expression if 4 and 7 are interchanged and also ‘×’ and ‘÷’ are interchanged? [Group - D 09/09/2022 (Evening)]

63 × 3 - 4 + 18 ÷ 7

Correct Answer: (b) 86
Solution:

Given,
63 × 3 - 4 + 18 ÷ 7
According to question By interchanging ( 4 and 7 ) and ( × and ÷ ) we get,
63 ÷ 3 - 7 + 18 × 4 = 86 (ans)

9. Which of the below two signs should be interchanged to make the following equation correct? [Group - D 12/09/2022 (Afternoon)]

75 ÷ 8 × 6 + 24 - 6 = 31

Correct Answer: (d) ÷ and -
Solution:

75 ÷ 8 × 6 + 24 - 6 = 31
By using Hit and Trial method, (By choosing option one by one) we get,
By interchanging (÷ and -)
75 - 8 × 6 + 24 ÷ 6 = 31
L.H.S.= 75 - 48 + 4 = 31 = R.H.S.

10. 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 - 5 ÷ 6 + 4 = ?

Correct Answer: (a) 32
Solution:

18 × 3 - 5 ÷ 6 + 4 = ?
After arranging the signs as per given instructions we get,
18 ÷ 3 × 5 + 6 - 4 = 6 × 5 + 2 = 32