Question

what sum of money will amount to Rs 840 in 3 years at 4 per cent interest per year​

Answer 1

here your answer of this question 750

Answer 2

$\textbf{\underline{\underline{Answer :-}}}$

Rs.750 amounts to Rs.840 in 3 years at 4 per cent interest per year.

$\textbf{\underline{\underline{Explanation :-}}}$

Given :

Amount money = Rs.840

In = 3 years

Rate of interest = 4 %

To find :

The sum of money which amounts to Rs.840 in 3 years at 4 per cent interest per year.

Solution :

Here,

Consider Principal as x

Amount = 840

Time = 3 years

Rate = 4 %

★ SI = Amount - Principal

Consider SI as = 840 - x

$\star$ As we know :

$\boxed{\sf{ SI = \dfrac{Principal \times Rate \times Time}{100}}}$

$\sf{\implies}84 0 - x = \dfrac{x \times 3 \times 4}{100}$

$\sf{\implies}840 - x = \dfrac{12x}{100}$

$\sf{\implies}100(840 - x) = 12x$

$\sf{\implies}84000 - 100x = 12x$

$\sf{\implies}84000 = 12x + 100x$

$\sf{\implies}84000 = 112x$

$\sf{\implies}x = \dfrac{84000}{112}$

$\sf{\implies}x = 750$

$\boxed{\sf{Principal = Rs.750}}$

Simple Interest = Amount - Principal

$\sf{\implies}$ 840 - 750

$\sf{\implies}$ 90

$\boxed{\sf{\red{Principal = Rs.750}}}$

$\boxed{\sf{\red{Simple \: Interest= Rs.90}}}$

$\therefore$ Rs.750 amounts to Rs.840 in 3 years at 4 per cent interest per year.

$\textbf{\underline{\underline{Verification :-}}}$

$\sf{\implies}90 = \dfrac{750\times 3 \times 4}{100}$

$\sf{\implies}90 = \dfrac{750 \times 12}{100}$

$\sf{\implies}90 = \dfrac{9000}{100}$

$\sf{\implies}90 = 90$

$\therefore$ Rs.750 amounts to Rs.840 in 3 years at 4 per cent interest per year.