Question Number 179848 by Mr.D.N. last updated on 03/Nov/22
$$ \\ $$$$\:\:\mathrm{In}\:\mathrm{how}\:\mathrm{many}\:\mathrm{years}\:,\mathrm{Rs}\:\mathrm{50000}\:\mathrm{amounts}\:\mathrm{to}\:\mathrm{Rs672720} \\ $$$$\mathrm{at}\:\mathrm{compounded}\:\mathrm{annually}\:\mathrm{if}\:\mathrm{the}\:\mathrm{interest}\:\mathrm{rate}\:\mathrm{is}\:\mathrm{1}\:\mathrm{paisa}\:\mathrm{per} \\ $$$$\mathrm{rupee}\:\mathrm{per}\:\mathrm{month}? \\ $$
Commented by mr W last updated on 03/Nov/22
$$\mathrm{100}\:{paisa}\:=\:\mathrm{1}\:{rupee}\:? \\ $$$${if}\:{yes},\:{then} \\ $$$$\mathrm{50000}\left(\mathrm{1}+\frac{\mathrm{12}}{\mathrm{100}}\right)^{{n}} =\mathrm{672720} \\ $$$$\Rightarrow{n}=\frac{\mathrm{log}_{\mathrm{10}} \frac{\mathrm{672720}}{\mathrm{50000}}}{\mathrm{log}_{\mathrm{10}} \mathrm{1}.\mathrm{12}}\approx\mathrm{23}\:{years} \\ $$