   Web Development : Starting from Concept, HTML, CSS, Web Site Develpment to Website Launching.
Written by: Sanjay Srivastava
B.Tech (Honours);IIT Kharagpur
PMP ; PMI USA

Class - VIII - Maths:- INDEX

1. Squares & Square Roots
2. Cubes & Cube Roots
4. Profit Loss & Discount
5. Compound Interest
6. Algebraic Identities 7. Polynomials 8. Linear Equations 9. Parallel Lines 10. Types of Quadrilaterals 11. Construction of Quadrilaterals 12. Circles 13. Areas 14. Surface Areas 15. Volumes 16. Statistics Class - VIII - Maths

## What is Compound Interest Formula (Page 2/3)

Important Tips (1) Be careful to read during the exam regarding the formula of simple interest or compound interest.
(2) If the interest rate is doubled / tripled, then the simple interest rate will get doubled / tripled. In case of compound interest the increase will be more than the increase of rate of interest

Question - Type 2 - What is the loss in interest if Rs 20000 deposited for 3 years at interest rate of 10% per annum and simple interest is calculated in place of compound interest.

Answer - 2- Simple Interest = 20000 * 3 * 10 /100
20000 * .3 = Rs 6000

Compound Interest = 20000 *((1+10/100)^3-1)
= 20000 * ((1.1)^3-1)) = 20000 (.331) = Rs 6620
Therefore loss = C.I. - S.I.
= 6620 - 6000 = Rs 620

Question - Type 3 - If the interest rate in the previous questions is doubled. Will interest will be doubled in both the cases i.e. simple and compound interest.

Answer - 3- YES & NO - In case of simple interest the interest amount will be doubled. But in the case of compound interest, it will be more than double. (refer next question on next page.)