Calculate the compound interest on Rs. 80,000 for 3 years if the rate of interest for the 3 successive years are 4%, 5% and 10% respectively.

Given:

Principal $P=Rs.\ 80000$

Rate of interest for 3 successive years $R_1, R_2$ and $R_3$ are $4 \%, 5 \%$ and $10 \%$ respectively.

Time $T= 3$ years

To do:

We have to find compound interest.

Solution:

We know that,

$A = P(1 + \frac{R_1}{100}) (1 + \frac{R_2}{100})(1+\frac{R_3}{100})$

A - Amount

P - Principle                   

R - Rate of Interest

Here,

$P = 80000, R_1 = 4 \%, R_2 =5 \%, R_3=10 \%$  

$A = 80000(1 + \frac{4}{100}) (1 + \frac{5}{100})(1 + \frac{10}{100})$

$A =  80000(1 + \frac{1}{25}) (1 + \frac{1}{20})(1 + \frac{1}{10})$

$A =  80000 (\frac{26}{25}) (\frac{21}{20})(\frac{11}{10})$

$A = \frac{80 \times 26 \times 21 \times 11}{5}$

$A = 16\times6006$

$A =  96096$

Amount  $=Rs.\ 96096$

Compound Interest $=$Amount$-$Principal

Compound Interest $= Rs.\ (96096-80000)$ 

Compound Interest $=Rs.\ 16096$.