RRB NTPC Maths Percentage: Tips, Tricks and Solved Problems

RRB NTPC Maths Percentage: The Railway Recruitment Board (RRB) NTPC (Non-Technical Popular Categories) exam is one of the most sought-after competitive exams for candidates aiming to work in the Indian Railways. The Maths section of the RRB NTPC exam can be challenging, and one of the most important topics is Percentage. Understanding percentage questions, mastering percentage tricks, and practicing percentage solved problems will give you the confidence you need to ace this section.

Here, we have provided the essential tips and tricks for solving percentage-related questions in the RRB NTPC Maths section, along with some solved examples to enhance your understanding.

RRB NTPC Maths Percentage

In mathematical terms, a percentage is a fraction of 100. It is a way of expressing a number as a fraction of 100. The symbol "%" represents the term "per hundred." For example, 25% means 25 out of 100 or 25/100.

Basic Formula for Percentage Calculation:

• Percentage Formula:
  Percentage = (Part / Whole) × 100
  Where:

• Part is the portion of the whole value you are interested in.

• Whole is the total value.

• Finding Part from Percentage:
  Part = (Percentage × Whole) / 100

• Finding Whole from Percentage:
  Whole = (Part × 100) / Percentage

Types of Percentage Questions in RRB NTPC Exam

The percentage questions in the RRB NTPC exam can be classified into the following categories:

1. Basic Percentage Calculation:

• These questions ask to calculate the percentage of a number or find the percentage increase/decrease.

2. Percentage Based on Profit and Loss:

• Questions related to profit and loss often involve percentage calculations. This includes finding profit percentage, loss percentage, and selling price or cost price.

3. Percentage Increase and Decrease:

• These questions deal with the concept of increase and decrease in values by a certain percentage.

4. Discount Percentage:

• A common topic in percentage questions is finding the discount percentage, especially in questions based on MRP (Marked Price) and Selling Price.

5. Interest and Compound Interest:

• Percentage is used extensively in problems involving simple interest and compound interest.
  
  

6. Data Interpretation:
   
   

• Percentage is often used in data interpretation questions, where data is given in the form of percentages.

Percentage Tricks for Fast Calculation

To solve percentage questions efficiently in the RRB NTPC exam, you must use a few percentage tricks to save time and reduce errors.

1. Converting Percentage to Fraction and Vice Versa

• To Convert a Percentage to a Fraction:
  
  

• Simply divide the percentage by 100. For example, 25% = 25/100 = 1/4.
  
  

• To Convert a Fraction to a Percentage:
  
  

• Multiply the fraction by 100. For example, 3/4 = 3/4 × 100 = 75%.
  
  

2. Finding 10%, 20%, 50% of a Number

• To find 10% of a number, just move the decimal one place to the left.
  Example: 10% of 200 = 20.
  
  

• To find 20%, find 10% and multiply it by 2.
  Example: 20% of 150 = 15 × 2 = 30.
  
  

• 50% is half of the number.
  Example: 50% of 80 = 40.
  
  

3. Quick Way to Find 1% of a Number

To find 1% of any number, move the decimal two places to the left.
Example: 1% of 3500 = 35.

4. Increase/Decrease in Percentage

To calculate the increase or decrease in percentage, use the formula:
Percentage Change = ((New Value - Old Value) / Old Value) × 100

For example, if a product's price increased from ₹200 to ₹250:
Percentage Increase = ((250 - 200) / 200) × 100 = 25%

5. Use of the Proportions Method for Profit and Loss Questions

In profit and loss questions, use the following proportion method to quickly find the percentage:
Profit or Loss Percentage = (Profit or Loss / Cost Price) × 100
For example, if an item was bought for ₹500 and sold for ₹600, the profit percentage is:
Profit = 600 - 500 = ₹100
Profit Percentage = (100 / 500) × 100 = 20%

Solved Percentage Problems for RRB NTPC Exam

Let’s solve a few percentage problems that you might encounter in the RRB NTPC Maths section.

Problem 1: Basic Percentage Calculation

Question:
A student scored 75 marks out of 100 in an exam. What is his percentage score?

Solution:
Using the percentage formula:
Percentage = (Marks Obtained / Total Marks) × 100
Percentage = (75 / 100) × 100 = 75%
So, the student scored 75%.

Problem 2: Profit Percentage

Question:
A shopkeeper bought an article for ₹250 and sold it for ₹300. What is the profit percentage?

Solution:
First, calculate the profit:
Profit = Selling Price - Cost Price = 300 - 250 = ₹50
Now, calculate the profit percentage:
Profit Percentage = (50 / 250) × 100 = 20%
The profit percentage is 20%.

Problem 3: Percentage Increase

Question:
The price of a book was ₹150, and now it is ₹180. What is the percentage increase in the price?

Solution:
Using the percentage change formula:
Percentage Increase = ((180 - 150) / 150) × 100 = (30 / 150) × 100 = 20%
So, the percentage increase in price is 20%.

Problem 4: Discount Percentage

Question:
An item’s MRP is ₹2000, and the discount given is 15%. What is the selling price?

Solution:
To find the discount amount:
Discount = (15 / 100) × 2000 = ₹300
Now, subtract the discount from the MRP:
Selling Price = 2000 - 300 = ₹1700
The selling price after the discount is ₹1700.

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