# Revision Notes for Part A: Mastering the Concept of Symbols & Notations (Download PDF)

By Renuka Miglani|Updated : December 28th, 2021

Hi Aspirants,

With only a few days left for CSIR NET 2022 exam, you should devote all your time in revising your concepts and topics. Practice as many mocks as you can to work on your speed and accuracy. At this high time, you should practice a lot of questions of those topics which have high chances of being asked in the exam. Symbols & Notations is one of the important and most scoring topics of the General Aptitude (Part A) through which one can score full marks in this section.

We've come up with the concept of Similarities & Differences for the upcoming exam CSIR-NET 2021. Scroll down the article below and learn this concept to crack the exam.

## Concept of Reasoning: Similarities & Differences

The Reasoning section of every competitive exam includes questions from the topic “Symbols & Notation”. Here, we are uploading different types of questions that will surely help you in the upcoming Exams. This topic deals with the questions on the basics of fundamental operations — addition, subtraction, multiplication and division. Sometimes, the questions involving these operations are set using artificial symbols. The candidate has to substitute the real signs and solve the questions accordingly to get the answer.

NOTE: While solving a mathematical expression, proceed according to the rule BODMAS i.e., Brackets, of, Division, Multiplication, Addition, Subtraction.

TYPE 1: Problems Based on Substitution:

Question 1: If 'A' stands for 'subtraction', 'B' stands for 'multiplication', 'C' stands for ‘addition', and 'D' stands for 'division', then what is the value of the following expression?

27 A 8 B 5 C (11 C 3) B 5 C 36 D 6

Solution: Given that:

'A' stands for 'subtraction', 'B' stands for 'multiplication', 'C' stands for 'addition', and 'D’ stands for ‘division’

So, 27 A 8 B 5 C (11 C 3) B 5 C 36 D 6

= 27 – 8 × 5 + (11 + 3) × 5 + 36 ÷ 6

Now solve the expression

27 – 8 × 5 + (11 + 3) × 5 + 36 ÷ 6 by using BODMAS rule.

27 – 8 × 5 + (11 + 3) × 5 + 36 ÷ 6

= 27 – 40 + 14 × 5 + 6

= 27 – 40 + 70 + 6 = 33 + 30 = 63

Question 2: If '<' means 'minus', '>' means 'plus', ‘=’ means 'multiplied by' and '\$' means ‘divided by', then what would be the value of

63 > 21 \$ 3 = 7?

Solution:

63 > 21 \$ 3 = 7

After putting the signs

63 + 21 ÷ 3 × 7

63 + 7 × 7

63 + 49 = 112.

Type 2: Problem Based on Interchange of Signs and Numbers:

Question 1: Which two signs should be interchanged to make the given equation correct?

225 + 5 × 3 ÷ 5 – 7 = 133

1. + and ÷
2. – and ×
3. + and ×
4. – and ÷

Solution: Given expression is

225 + 5 × 3 ÷ 5 – 7 = 133

After interchanging

225 ÷ 5 × 3 + 5 – 7 = 133

Apply BODMAS,

225 ÷ 5 × 3 + 5 – 7 = 133

Or, 45 × 3 – 2 = 133

Or, 135 – 2 = 133

Or, 133 = 133

As we got the correct answer, so no need to check more options.

Hence, option (a) is the correct answer.

TYPE 3: Based on Equation Balancing:

Question: Select the correct combination of mathematical signs to sequentially replace the * signs, to balance the following equation.

(14 * 9 * 6) * 15 * 8

1. ×, =, ÷, –
2. ×, –, ÷, =
3. –, ÷, ×, =
4. ÷, –, =, ×

Solution:

on checking option (a)

(14 * 9 * 6) * 15 * 8

after putting signs

(14 × 9 = 6) ÷ 15 – 8 (incorrect)

on checking option B

(14 * 9 * 6) * 15 * 8

after putting signs

(14 × 9 – 6) ÷ 15 = 8

(126 – 6) ÷ 15 = 8

120 ÷ 15 = 8

8 = 8

Signs in option (b) satisfied the above equation,

So, no need to check other options.

Hence, option (b) is the correct answer.

Question 1: The two given expressions on both the side of the '=' sign will have the same value if two numbers from either side or both sides are interchanged. select the correct numbers to be interchanged from the given options.

3 + 5 × 4 – 24 ÷ 3 = 7 × 4 – 3 + 36 ÷ 6

1. 5, 7
2. 4, 7
3. 6, 3
4. 24, 36

Solution: Check option (a)

Given expression is

3 + 5 × 4 – 24 ÷ 3 = 7 × 4 – 3 + 36 ÷ 6

After interchanging

3 + 7 × 4 – 24 ÷ 3 = 5 × 4 – 3 + 36 ÷ 6

Apply BODMAS,

3 + 28 – 8 = 20 – 3 + 6

Or, 3 + 28 – 8 = 20 – 3 + 6

Or, 3 + 20 = 23

So, 23 = 23

As we got the correct answer, so no need to check more options.

Hence, option (a) is the correct answer.

→ If you have any questions feel free to ask in the comments section below.

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