Mathematical Operations – Railway Reasoning (part – 5)

Total Questions: 26

1. If ‘÷’ means division, ‘-’ means multiplication, ‘×’ means addition, and ‘+’ means subtraction, then what will be the value of the following expression [RRB NTPC 24/07/2021 (Evening)]

7 × 4 + 2 - 3

Correct Answer: (d) 13
Solution:

7 × 4 + 2 - 3
= 7 + 4 ÷ 2 × 3 = 13

2. If ‘-’ stands for ‘×’, ‘+’ stands for ‘÷’, ‘×’ stands for ‘+’, and ‘÷’ stands for ‘-’, then find the value of [RRB NTPC 26/07/2021 (Morning)]

24 + 6 ÷ 2 - 9 × 4

Correct Answer: (a) -10
Solution:

24 + 6 ÷ 2 − 9 × 4
According to question,
24 ÷ 6 − 2 × 9 + 4 = −10;

3. If ‘S’ denotes ‘×’, ‘B’ denotes ‘-’, ‘R’ denotes ‘+’, and ‘V’ denotes ‘÷’, then what will be the value of the following expression? [RRB NTPC 26/07/2021 (Morning)]

14 S 63 V 21 R 19 B 22

Correct Answer: (c) 39
Solution:

If ‘S’ denotes ‘×’, ‘B’ denotes ‘-’, ‘R’ denotes ‘+’, and ‘V’ denotes ‘÷’,
Then the value of the following expression is :
14 S 63 V 21 R 19 B 22
= 14 × 63 ÷ 21 + 19 - 22 = 39

4. If ‘P’ means ‘×’, ‘Q’ means ‘÷’, ‘R’ means ‘+’ and ‘S’ means ‘-’, then what will be the value of the following expression? [RRB NTPC 26/07/2021 (Evening)]

32 R 16 Q 8 S 3 P 2

Correct Answer: (d) 28
Solution:

32 R 16 Q 8 S 3 P 2
= 32 + 16 ÷ 8 − 3 × 2
= 32 + 2 − 6 = 34 − 6 = 28

5. Which two signs should be interchanged to make the following equation correct? [RRB NTPC 26/07/2021 (Evening)]

17 ÷ 65 × 13 + 11 - 10 = 86

Correct Answer: (b) ÷ and ×
Solution:

17 ÷ 65 × 13 + 11 − 10 = 86
Interchange signs
= 17 × 65 ÷ 13 + 11 − 10
= 17 × 5 + 11 − 10 = 85 + 11 − 10
= 96 − 10 = 86 = RHS

6. If ‘+’ means ‘×’, ‘×’ means ‘-’, ‘-’ means ‘+’ and ‘÷’ remains unchanged, then finds the value of the following expression. [RRB NTPC 31/07/2021 (Morning)]

18 ÷ 6 + 12 × 2 - 5

Correct Answer: (c) 39
Solution:

18 ÷ 6 + 12 × 2 − 5
= 18 ÷ 6 × 12 − 2 + 5
= 3 × 12 − 2 + 5 = 36 − 2 + 5
= 41 − 2 = 39

7. If ‘÷’ means ‘division’, ‘+’ means ‘subtraction’, ‘×’ means ‘addition’ and ‘-’ means multiplication, then find the value of 15 + 32 × 4 ÷ 8 - 2. [RRB NTPC 31/07/2021 (Evening)]

Correct Answer: (b) -1
Solution:

15 + 32 × 4 ÷ 8 − 2
= 15 − 32 + 4 × 8 ÷ 2
= 15 − 32 + 16
= 31 − 32 = -1

8. In the following question, correct the equation by interchanging the two signs. [RRB JE 22/05/2019 (Afternoon)]

7 + 10 ÷ 5 - 5 = 10

 

Correct Answer: (c) + and -
Solution:

Given, 7 + 10 ÷ 5 - 5 = 10
By checking all the options one by one we found that only option (c) satisfies so
as per that,
7 - 10 ÷ 5 + 5 = 10
From L.H.S.
7 - 2 + 5 = 10 = R.H.S.

9. If '+' means '÷', '-' means '+', '÷' means '×' and '×' means '-', then 32 + 4 - 8 × 4 ÷ 3 = ? [RRB JE 22/05/2019 (Evening)]

Correct Answer: (b) 4
Solution:

Given, 32 + 4 - 8 × 4 ÷ 3
As + → ÷, - → +, ÷ → ×, × → -
Applying condition we get,
32 ÷ 4 + 8 - 4 × 3 = 16 - 12 = 4

10. Choose the correct order of signs from the options so as to make the equation correct. [RRB JE 24/05/2019 (Evening)]

18 - 5 × 50 = 40

 

Correct Answer: (d) ×, -, =
Solution:

Given, 18 - 5 × 50 = 40
By checking all the options one by one we found that only option (d) satisfies so
as per that,
18 × 5 - 50 ⇒ 90 - 50 = 40