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If a sum of money double itself in 8 years, then the interest rate in percentage is ?

1 $8 \frac{1}{2}$ $8\frac{1}{2}$ %
210%
3 $10 \frac{1}{2}$ $10\frac{1}{2}$ %
4 $12 \frac{1}{2}$ $12\frac{1}{2}$ %

Answer:- 1

Explanation:-

Solution:

Money is double itself means interest is equal to money.

\begin{aligned} P  = \frac{P \times 8 \times r}{100} \\ \Rightarrow r  = \frac{100}{8} \\ \Rightarrow r  =  12 \frac{1}{2} % \end{aligned}

$\eqalign{ & {\text{P = }}\frac{{{\text{P}} \times {\text{8}} \times {\text{r}}}}{{100}} \cr & \Rightarrow {\text{r = }}\frac{{100}}{8} \cr & \Rightarrow {\text{r = 12}}\frac{1}{2}\% \cr}$

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", "dateCreated": "7/24/2019 10:09:12 AM", "author": { "@type": "Person", "name": "Nitin Sir" } }, "suggestedAnswer": { "@type": "Answer", "text": "

Solution:

Money is double itself means interest is equal to money.

\begin{aligned} P  = \frac{P \times 8 \times r}{100} \\ \Rightarrow r  = \frac{100}{8} \\ \Rightarrow r  =  12 \frac{1}{2} % \end{aligned}

$\eqalign{ & {\text{P = }}\frac{{{\text{P}} \times {\text{8}} \times {\text{r}}}}{{100}} \cr & \Rightarrow {\text{r = }}\frac{{100}}{8} \cr & \Rightarrow {\text{r = 12}}\frac{1}{2}\% \cr}$ ", "dateCreated": "7/24/2019 10:09:12 AM" } }

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