Question

A sum of money put at 11% per annum amount Rs 4491 in 2 years 3 months. What will it amount to in 3 years at the same rate?

Answer 1

Hint:
The amount in 2 years 3 months at a rate of 11% is 4491. From this we can find the principal for finding this we have to find the simple interest from $S.I = \dfrac{{P \times R \times T}}{{100}}$ then put the values of S.I in $\text{amount = Principal + S.I.}$ and then. Using the same formulas, we can calculate the amount for 3 years.

Complete step by step solution:
Given rate of interest= 11%
Time= 2year 3 months
=$2 + \dfrac{3}{{12}}years$=$\dfrac{9}{4}years$
And principal=P
And $S.I = \dfrac{{P \times R \times T}}{{100}}$
Then $S.I = \dfrac{{P \times 11 \times 9}}{{100 \times 4}}$
$\therefore S.I = \dfrac{{99P}}{{400}}$
Given amount =4491
And $\text{amount = Principal + S.I.}$
$4491 = p + \dfrac{{99P}}{{400}}$
$ \Rightarrow p = \dfrac{{4491 \times 400}}{{499}}$
$P = 3600$
Now, we have to calculate S.I for 3-years
$P = 3600$
t= 3 years
rate of interest= 11%
$S.I = \dfrac{{3600 \times 11 \times 3}}{{100}} = 1188$
Amount for 3 years is $\text{amount = Principal + S.I.}$

$Amount = 3600 + 1188 = 4788$

Note:
Formula used for the calculating S.I is $S.I = \dfrac{{P \times R \times T}}{{100}}$ where P is principal R is rate of interest per annum and T is the time in a year. And for $\text{amount = Principal + S.I.}$. Conversion unit of.