Question

Gayathri invested a sum of Rs. $12,000$ at $5$% p.a. at compound interest. She received an amount of $13,230$ after '$n$' years. Find the value of '$n$'.

Answer 1

Interest for the $1$st year$=\frac{12000\times 5\times 1}{100}$

$=600$

Amount After the $1$st year$=12000+$Rs$600$

$=12600$

Interest for the $2$nd year$=\frac{12600\times 5\times 1}{100}$

$=630$

Amount After the $2$nd year$=12600+$Rs$630$

$=13230$

$\therefore$Required value of ${}^{\prime }{n}^{\prime }$$=2$years.