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RD Sharma Class 7 Maths Solutions Chapter 13 - Simple Interest

Last updated date: 04th Mar 2024
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IVSAT 2024

RD Sharma Solutions for Class 7 Maths Chapter 13 - Simple Interest - Free PDF Download

Interest rates are an interesting and important mathematical concept. These interest rates are the backbone of our banking and finance sectors. A small change in these rates could have enormous and unexpected consequences for the economy. So, let’s first understand what interest is and the interest rates. Interest is a sum charged to someone who borrows a certain amount of money. This term is often used in the context of banks, loans, installment payments, and savings. It is directly associated with the percent, cost, and length of time that the money is lent for. There are many different forms of interest that can be used. The simplest and most popular form of interest is simple interest. For small sums of money, this form of interest is applicable for a limited period of time, typically days, weeks, months, or even a few years. RD Sharma Class 7 Solutions Chapter 13 provides exclusive content about Simple interest and solutions to important questions.

RD Sharma Class 7 Simple Interest is based on the NCERT curriculum and CBSE syllabus. These solutions will help students to prepare for their board exams as well as apply these concepts in their real-life situations too. Students can download RD Sharma Class  7 Solutions Chapter 13 free PDF available on the Vedantu platform.

RD Sharma Class 7 Simple Interest

The RD Sharma Solutions for Class 7 Maths Chapter 13 are developed by experts who have a lot of experience in teaching the subject. These solutions are carefully designed in a step-by-step manner with the utmost care to make students understand the concepts easily and ace their exams.

Here let us look into a few of the important topics from the Simple interest chapter which are frequently asked in the exams.

  • Definition of principal

  • Definition and meaning of interest

  • Formula to calculate the amount

  • Definition and meaning of simple interest

  • Formula to calculate simple interest

  • Verbally related problems on simple interest

Definition of principal

The principal amount which is denoted by the letter (P) is actually the initial or original amount of the loan, or the initial amount invested.

Definition and Meaning of Interest

Interest is the amount paid for borrowing others’ money. 

When we borrow money, we have to pay interest. When we lend money to borrowers, we get paid interest. 

It is an additional amount of money that is paid by the borrower to a lender apart from the amount borrowed. 

Suppose you borrowed Rs. 10 from your friend and you pay him Rs. 12 after a week. Here the additional amount of Rs. 2 is the interest

Formula to Calculate the Amount

The formula to calculate the amount is the principal amount plus the simple interest i.e. 

Amount = Principal + Simple interest

Definition and Meaning of Simple Interest

Simple Interest or (S.I.) is the process of computing the amount of interest for a principal amount of money at any particular rate of interest. The whole notion of simple interest depends on the time worth of money.

For illustration, a contractor Ms. Alexis wants to start a company and so she requested a bank to grant her a loan. The bank allowed her a sum of Rs 50,000/- for 4 years. At the end of four years, Alexis will have to return the money to the bank. She cannot just pay back the 50,000/-. It costs to borrow/loan money. The bank charges an 8.5% interest. So, Ms. Alexis must pay interest at the agreed 8.5% per annum.

Formula to Calculate Simple Interest

The formula for calculating simple interest is

Simple Interest (SI)     =   \[ \frac{P\times R\times T}{100}\]


P =principal amount,

R =rate of interest

T =time period of interest.

Summary points for Calculating Simple Interest

  • Simple Interest is calculated based on the amount borrowed and the time period until the return.

  • The initial amount borrowed from the lender for a given time is called the principal.

  • The extra money owed is called simple interest.

  • Interest is the extra money that the borrower gives for utilizing the lender’s money.

  • The time for which the money is borrowed is called the time period.

  • The whole amount of money paid back after the stipulated time is called the amount.

Verbally Related Problems on Simple Interest

Q. An invested amount retrieves an interest of Rs.5000 at the rate of 10% in one year. What was the principal amount?

Solution: Let the principal amount be P, SI be the simple interest, R be the rate of interest, and T the time period.


Simple Interest (SI)        =   \[ \frac{P\times R\times T}{100}\]  = \[\frac{5000\times 10\times 1}{100}\] = 500

The principal amount is Rs.500.

Q.Alexa took a vehicle loan of Rs. 50000 on 28 February 2020 at the rate of 8% p.a. and paid it back on 16th July 2020. Find the total amount paid by Alexa?



P = Rs.50,000

R = 8 % p.a.

T = 139/365


Time = Feb + March + April + May + June + July

         = 1 + 31  + 30  + 31  + 30  + 16 

         = 139 days


Simple Interest (SI)     =   \[ \frac{P\times R\times T}{100}\]

Simple Interest (SI)     =   \[\frac{50000\times 8\times 139}{100\times 365}\]

= Rs.1523.30

Hence, the amount paid by Alexa = Rs (50,000 + 1523.30) = Rs.51,523.30

We have provided step-by-step solutions for all exercise questions given in the pdf of Class 7 RD Sharma Chapter 13 - Simple Interest. All the Exercise questions with solutions in Chapter 13 - Simple Interest are given below:

Exercise 13.1


Exams Preparation Tips Using RD Sharma Class 7 Simple Interest

Students can improve their reasoning and analytical skills by solving various types of questions. RS Aggarwal Solutions provides all answers to the questions in this chapter, as well as improves the speed at which questions are answered. These tips often help the student in effectively preparing for the final exams and will come in handy for students while attempting any questions from the Simple Interest chapter.

  • Recall the concepts of ratios and percentages before attempting the questions from SImple interest.

  • Understand the concepts of Interest, profit and loss, and discounts clearly and then start with the Simple Interest concept.

  • Remember the basic formulas of simple interest to solve the questions in quick time.



The expense of using or borrowing money without compound interest or interest on interest is known as simple interest. It's pretty simple to calculate because all you need is the principal sum borrowed and the time period. When you're a creditor, simple interest works in your favor because it holds the total sum you pay lower than it would be with compound interest. When you're an investor, though, it can work against you because you want your returns to compound as much as possible to get the most out of your investment. The RD Sharma Class 7 Simple Interest prepared by Vedantu experts will be really helpful for students when preparing for their board exams. The RD Sharma solutions also have a lot of practice questions for students to prepare for their exams with more confidence. The solutions are designed in such a way that students will get a unique and fun way of learning when referring to the RD Sharma Solutions for Class 7 Maths Chapter 13.

FAQs on RD Sharma Class 7 Maths Solutions Chapter 13 - Simple Interest

1. What is simple interest?

The concepts of simple interest are very important for us to understand in real life. If a student goes through the above article, they will very easily understand the important concept of simple interest.

Simple Interest is the method of calculating the amount of interest for a principal amount at any given rate of interest.

Thus, students are able to understand what simple interest actually means. The concept of simple interest is commonly used in banks while giving loans.

2. What are the principal and amount?

In the chapter, the principal is a very important concept which students must understand. In order to describe principal in simple words, we can say:

The amount which is borrowed from the lender for any given time period is called the principal.

Thus, we are able to understand that principle is the sum that is borrowed by the borrower or lent by the lender during a transaction.

The amount is another important concept that students usually get confused with while solving questions on the chapter of simple interest. 

In simple words we can say:

The amount is the sum of principal and simple interest. It is the actual amount paid to the lender after the given time period.

Thus, to summarise:

Amount=Principal+Simple interest

3. What is the use of simple interest in real life?

After studying the chapter of simple interest, students must be wondering about the real-life applications of the chapter.

It is very important for us to apply what we studied in real life to understand the true essence of a chapter.

The concept of simple interest is utilized in real-life scenarios such as businesses, loans, purchases, discounts, etc. It is very useful to have an idea about simple interests to understand how the world works.

Thus, students are able to appreciate the concepts learned in the chapter.