   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 1/3)

Important Tips (1) Simple Interest = (P * T * R)/100
[ P=Principal; R=Rate of interest; T=Time]
Please make sure that the both 'Time' and 'Rate of interest' are in the same reference .i.e. years / months / days
C.I. = Compound Interest; n=No of period

Question - Type 1 -
Find the compound interest on Rs 10000/- for 3 years @ 10 % annually, by simple interest and compound interest formula.

Refer the formulas shown in left side.
By Simple Interest Method - Since the question is for compound interest annually, therefore we have to calculate annually.
(a) Interest for 1st year = 10000 * 1 * 10/100 = 1000
P after 1 year = 10000+1000=11000
(a) Interest for 2nd year = 11000 * 1 * 10/100 = 1100
P after 1 year = 11000+1100=12100
(a) Interest for 3rd year = 12100 * 1 * 10/100 = 1210
P after 1 year = 12100+1210=13310
Therefore Interest = 13310 - 10000 = Rs 3310

By Compound Interest Method - P=10000 R=10 n=3  = 10000 [(1.331)-1] = 10000 * .331 = Rs 3310