Question

Find the sum which will amount to Rs 4590 at 12% per annum in 3 years.

Answer 1

$\huge\mathfrak{\underline{solution}}$

let , the sum is = P Rs

Given

time(t)= 3 years

$sum \: with \: interest( \bf{P}_{I}) = 4590$

rate of interest (r)= 12%

❍Compound interest

$\large{ \underline{USING \: FORMULA}}$

$\: \: \: \: \: \: \: \: \: \: \: \: \: \large{\boxed{P_I= P(1+\frac{r}{100}){}^{t}}}$

So, putting the values

$\large\implies \large{P_I= P(1+\frac{r}{100}){}^{t}} \\ \large\implies4590 = P(1 + \frac{12}{100} ) {}^{3} \\ \large\implies 4590 = P( \frac{112}{100} ) {}^{3} \\ \large\implies4590 \times (\frac{100}{112} ) {}^{3} = P \\ \large\implies P = 3267.07 \:Rs\: (approx)$

❍Simple interest

$\large{ \underline{USING \: FORMULA}}$

$\large{\boxed{I= \frac{Prt}{100} }} \implies \large{\boxed{ P_I = P + \frac{Prt}{100} }}$

So, putting the values

$\implies 4590 = </p><p>P + \frac{P \times 12 \times 3}{100} \\ \implies4590 = P(1 + \frac{36}{100} ) \\ \implies p = 4590 \times \frac{100}{112} \\ \implies P = 4098.2 \: Rs\: (approx)$

Hope this helps you....