Question

A man sold his flat.He invested half of the money received at a compound interest of 6 % p.a and the other half at 10 % p.a for 3 years. He will get rupees 6305 04 after 3 years .At what price did he sell the flat?

Answer 1

Answer :

Let man sold his flat = x rupee
And
we know formula for compound interest , As :

Amount = P ${\left(1+\frac{r}{100}\right)}^t$ , Here

P = Principle amount ,

r = Rate of interest
And
t = Time in years

Given : He invested half of the money received at a compound interest of 6 % p.a and the other half at 10 % p.a for 3 years. He will get rupees 6305 04 after 3 years . , So we get

$$\begin{gathered} \Rightarrow \frac{x}{2}{\left(1+\frac{6}{100}\right)}^3+\frac{x}{2}{\left(1+\frac{10}{100}\right)}^3=630504 \\ \Rightarrow \frac{x}{2}{\left(1+\frac{3}{50}\right)}^3+\frac{x}{2}{\left(1+\frac{1}{10}\right)}^3=630504 \\ \Rightarrow \frac{x}{2}{\left(\frac{53}{50}\right)}^3+\frac{x}{2}{\left(\frac{11}{10}\right)}^3=630504 \\ \Rightarrow \frac{x}{2}\left[{\left(\frac{53}{50}\right)}^3+{\left(\frac{11}{10}\right)}^3\right]=630504 \\ \Rightarrow \frac{x}{2}\left[\left(\frac{148877}{125000}\right)+\left(\frac{1331}{1000}\right)\right]=630504 \\ \Rightarrow \frac{x}{2}\left[\left(\frac{148877+\hspace{0.17em}166375}{125000}\right)\right]=630504 \\ \Rightarrow \frac{x}{2}\left[\frac{315252}{125000}\right]=630504 \\ \Rightarrow \frac{157626x}{125000}=630504 \\ \Rightarrow 157626x=78813000000 \\ \Rightarrow x=\frac{78813000000}{157626} \\ \Rightarrow x=500000 \end{gathered}$$

So,

Man sold his flat At Rs 5,00,000 ( Ans )