Question

Chapter - compund interwst using formula
Question:-
On what sum of money will the compound interest for 2 years at 5% per annum amount to Rs.786.75?​

Answer 1

5 is the answer of this question

Answer 2

•Solution

P=?

C.I.=-P

$\sf \: C.I. = P {\huge{[}} (1 + \frac{r}{100} {)}^{n} - 1 \huge]$

$\sf768.75 =P{ \huge{[}}( 1 + \frac{5}{100} {)}^{2} - 1 \huge]$

$\rightarrow \sf768.45 = P {\huge{[}} (\frac{{ \cancel{105 }} \: \tiny{21}}{ \cancel{{100} } \: \tiny{20}} {)}^{2} - 1 \huge]$

$\sf \rightarrow768.75 = P( \frac{441 }{400} - 1)$

$\sf \rightarrow768.75 = \frac{41}{400} P$

$\sf \rightarrow\: P = \frac{768.25 \times 400}{41} \\ \\ \sf \implies P = \frac{ \cancel{307500}}{ \cancel{41}} = 7500$

So the sum of money is rs.7500 which wgen compounded annually for 2 years at the rate of 5% is rs.768.25

Hope it helps you...