RS Aggarwal Class 8 Chapter 11 Solutions (Compound Interest)

RS Aggarwal Class 8 Maths Solutions Chapter 11 ’Compound Interest’ is the best guide to practice the topics of the chapter and clear your concepts. In this chapter of RS Aggarwal Class 8 Maths Solutions, there are 4 exercises with around 63 questions. We have provided stepwise solutions to all the exercises of the chapter that would guide you in understanding how the questions related to compound interest are solved. 

The exercises that are given in RS Aggarwal Class 8 Maths Chapter 11 are based on the topics of compound interest and simple interest. Terms like rate of interest, time period, per annum, and half-yearly are also introduced in this chapter. You have to find the compound interest charged for different time periods like annually, two years, three years, and so on. In some questions, you are also required to find the value of an item after compound interest.

Compound interest is an important topic that would be very useful in your daily life. RS Aggarwal Class 8 Maths Chapter 11 provides ample questions to practice this concept. The chapter includes questions of mixed aptitude, perfectly suitable for the preparation of CBSE school exams along with competitive exams and olympiads. Refer to the solutions provided by us when you face any confusion in the chapter and ensure your smooth learning. 

Important Topics for RS Aggarwal Class 8 Maths Solutions Chapter 11: Compound Interest


  • Whenever we borrow money from a bank, or any other place, interest is charged on that money. 
  • For example, Ram borrowed Rs.10,000 from a local bank for one year on which an interest of 10% was charged. So, Ram would have to return Rs.11,000 to the bank after the decided amount of time. 
  • When we borrow money, there is a rate of interest (R) involved which decides how much interest would be charged. Also, the time period (T) defines the period for which the interest would be charged. 
  • For example, if Ram borrowed money from a bank at the rate of 3% per annum for 4 years then, 3% interest would be charged on that money for a time period of four years, and then he would have to return the money along with interest. 
  • The initial amount that is borrowed is known as the principal amount (P). 

Simple Interest

Simple Interest can be easily calculated with this formula: I = PRT, where I is the Interest Amount, P is the Principal Amount, R is the Rate of Interest and T is the Time Period. 

Compound Interest

  • Simple Interest is, however, a theoretical concept. In real-life situations, for example, banks, you are not charged a simple interest but compound interest.
  • For instance, you borrowed Rs.1000 from a bank for 3 years at a rate of 2%. The simple interest can be calculated as (1000 x 2 x 3)/100, that is, Rs.60. So, as per simple interest, after 3 years, you will have to pay Rs.1060 to the bank. 
  • But, in real-life situations, the principal amount of interest changes after a certain amount of time. 
  • For example, if you borrowed Rs.1000 from a bank for 3 years at a rate of 2% per annum. 

So, after one year the simple interest would be (1000 x 2 x 1)/100  , that is, Rs.20. Now, the amount for next year would be calculated on Rs.1020 and not Rs.1000. 

So, now the simple interest for the second year would be (1020 x 2 x 1)/100  , that is, Rs.20.4. Now, for the last year, the principal amount would be Rs.1040.4 

  • This is called compounding and the interest that is to be paid is called compound interest.
  • However, the calculation process is not that tough as we have a formula that can help you calculate the compound interest. It is given by the following:

A: Amount 

P: Principal 

R: Rate of Interest

T: Time  

Exercise Discussion for RS Aggarwal Solutions for Class 8 Maths Chapter 11: Compound Interest

  • All the four exercises of RS Aggarwal Class 8 Maths Chapter are very important for you as they help you revise the whole concept of compound interest multiple times. 
  • Exercise 11A has 8 questions that are very straightforward. You just have to calculate the simple interest and the compound interest using the formula. 
  • Exercise 11B has 30 questions with a slightly higher difficulty level. Here, you are given more than one rate of interest in the questions. In some questions, you are given the value of the final amount after applying the interest and you have to calculate the original value. 
  • Exercise 11C has only 10 word-problems and Exercise 11D has 15 word-problems. All are based on finding the compound interest. 
  • Practising these exercises will help you strengthen your calculation skills as well for competitive exams. 

Benefits of RS Aggarwal Class 8 Maths Solutions Chapter 11: Compound Interest by Instasolv

  • Now you can be exam ready easily with Instasolv’s RS Aggarwal Solutions for Class 8 Maths Chapter 11. 
  • These solutions are designed to help you understand the process of finding simple and compound interests. 
  • All the solutions are explained step by step with proper reasoning. 
  • These solutions are based on the latest CBSE Class 8 Maths syllabus so you can easily rely on them. 
  • All of these solutions are absolutely FREE!