Question

Find the difference between the compound interest and the simple interest on
* 30,000 at 7% per annum for three years.​

Answer 1

$\sf\large\underline\blue{Given:}$

$\tt{\implies Principal=Rs.30000}$

$\tt{\implies Rate=7\%}$

$\tt{\implies Time=3\: years}$

$\sf\large\underline\blue{To\: Find:}$

$\tt{\implies Difference\:_{(CI-SI)}=?}$

$\sf\large\underline\blue{Solution:}$

• To calculate the difference between compound interest and simple interest , at first we have to find out both simple interest and compound interest separately then subract to eachother.]

$\sf\small\underline\green{Calculation\:for\:SI:}$

$\sf\large\underline{Here,\:P=30000\:\:T=3\:\:R=7\%:}$

$\tt{\implies SI=\dfrac{P*T*R}{100}}$

$\tt{\implies SI=\dfrac{30000*3*7}{100}}$

$\tt{\implies SI=300*3*7}$

$\tt{\implies SI=Rs.6300}$

$\sf\small\underline\green{Calculation\:for\:CI:}$

$\sf\large\underline{Here,\:P=30000\:\:T=3\:\:R=7\%:}$

$\tt{\implies CI=P\bigg(1+\dfrac{r}{100}\bigg)^n-P}$

$\tt{\implies CI=30000\bigg(1+\dfrac{7}{100}\bigg)^3-30000}$

$\tt{\implies CI=30000\bigg(\dfrac{100+7}{100}\bigg)^3-30000}$

$\tt{\implies CI=30000\bigg(\dfrac{107}{100}\bigg)^3-30000}$

$\tt{\implies CI=30000*(1.07)^3-30000}$

$\tt{\implies CI=30000*1.225043-30000}$

$\tt{\implies CI=36,751.29-30000}$

$\tt{\implies CI=Rs.6,751.29}$

$\sf\large{Hence,}$

$\tt{\implies Difference\:_{(CI-SI)}=6751.29-6300}$

$\tt{\implies Difference\:_{(CI-SI)}=Rs.451.29}$