COMPOUND INTEREST BY: MAYANK AGNIHOTR

IMPORTANT FACTS AND FORMULAE COMPOUND INTEREST The system of interest in which amount after first unit of time becomes principal for the second unit, the amount after second unit becomes principle for the third unit and so on After a certain period, the difference between the amount and the money borrowed is called compound interest (C.I) for that period. Let Principle = P , Rate = R% pa, Time-n years * When interest compounded annually: Amount P(1+ 100 * When interest compounded half-yearly: Amount-P (1 + )'" 100 * When interest compounded Quaterly CI = Amount-Principal Amount = P ( 1 + (R/4) n 100

QUESTIONS Ques 1. The compound interest on Rs. 30,000 at 7% per annum is Rs.4347. Find the time (in years) So. Amount Rs. (30000 4347) Rs. 34347. Let the time be n years Then Amount - P(34347 30000 (1+10 n 34347 11449 30000 10000 107 2 100 . n 2 years Ans Ques 2. The value of a machine depreciates at the rate of 10% per year. It was purchased 3 years ago. If its present value is 1,45,800, for how much was it purchased? Sol R=-10 1-1 0)3 P(). 145800 = P ~ = 145800 P= 145800 1000 729 P 200,000 Rs Ans

Ques 3. The difference between simple and compound interests compounded annually on a certain sum of money for 2 years at 4% per annum is Rs 1. Find The sum (in Rs.) Sol Let the sum = x Rs (676x-x)= x| = (625 2 4 100) _xl 676 25 (X1402) = 25 51x 2x x = 625 Rs Ans 625 25 A Sum of money amounts to 4818 Rs after 3 years and 7227 Rs after 6 years on compound interest. Find the sum. Ques 4. Sol Let us assume the the money is compounded in the blocks of 3 years, so in 1st 3 years it becomes 4818 in next 3 years 7227. That is it gets 1.5 times because times of original Sum 7227 = 1.5 , in the 1st 3 years it also becomes 1.5 Sum = 4818 1.5 3212 Rs Ans

Ques 5. Albert invested an amount of Rs. 8000 in a fixed deposit scheme for 2 years at compound interest rate 5 % pa. How much amount will Albert get on maturity of the fixed deposit? Amount =18000 (1 + Amount- 8000 x Sol. 100 21 21 20 20 Amount=8820 Rs Ans. Ques 6. Find the least number of complete years in which a sum of money put out at 20% compound interest will be more than doubled. Sol. Let sum of money = P RS 20 n 100 6 (1.2)4 2.0736 n=4 Ans

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Mayank Agnihotri

B.Tech (ECE), Machine enthusiast, Inspired by an old hindi saying " Gyan baatne se badhta ha"

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Raghu Pabby

2 years ago

sir try to add one state daily so that we got for revision also before pt 18

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Basavaraj T Kattimani

a year ago

thanku sir garib bachho ko aap bahut madad kar rahe ho sir

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