Question

For what interest Rs. 30,000/- becomes in
three years Rs. 37,500/-?
(A) 6 1/4 percent
(B) 8 1/2 percent
(C) 7 1/2 percent
(D) 8 1/8 percent​

Answer 1

➤ Given :-

Principle :- ₹ 30000

Total amount :- ₹ 37500

Time :- 3 years

➤ To Find :-

Rate of interest for the given sum

➤ Formula required :-

${\tt \large \dashrightarrow \orange{\boxed{\tt \gray{\dfrac{SI \times 100}{P \times T}}}}}$

➤ Solution :-

First, we should find the value of the simple interest by subtracting the total amount and the principle

Simple Interest :-

${\tt \longrightarrow 37500 - 30000}$

${\tt \longrightarrow Rs \: \: 7500}$

Now,

Rate of interest :-

${\tt \longrightarrow \dfrac{7500 \times 100}{30000 \times 3}}$

${\tt \longrightarrow \dfrac{7500 \times \cancel{100}}{\cancel{30000} \times 3} = \dfrac{7500 \times 1}{300 \times 3}}$

${\tt \longrightarrow \dfrac{ \cancel{7500} \times 1}{ \cancel{300} \times 3} = \dfrac{25 \times 1}{1 \times 3}}$

${\tt \longrightarrow \dfrac{25}{3} = \boxed{\tt 8 \dfrac{1}{3} \bf\%}}$

$\Huge\therefore$ The rate of interest of the given sum is ${\tt 8 \dfrac{1}{3} \bf\%}$

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$\dashrightarrow$ Some related formulas :-

Simple Interest :- ${\boxed{\tt\dfrac{P \times R \times T}{100}}}$

Principle :- ${\boxed{\tt\dfrac{SI \times 100}{R \times T}}}$

Time :- ${\boxed{\tt\dfrac{SI \times 100}{P \times R}}}$