Question

If ₹4 becomes ₹10 in 50 years at simple interest, the rate % p.a. is

a) 5 %b) 2 1/2 %c) 3 1/3 %d) 3 %e) 6 %

Answer 1

Step-by-step explanation:

SI = Rs 6

SI = PRT /100

SI = 4 x R x 50 / 100

6 = 2R

R = 6/2

R = 3%

Ans is option d

Answer 2

➤ Given :-

Principle :- ₹ 4

Total amount :- ₹ 10

Time :- 50 years

➤ To Find :-

Rate of interest for the given sum.................

➤ Formula required :-

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

➤ Solution :-

First we should find the simple interest by subtracting the total amount and the simple interest............

Simple Interest :-

${\tt \longrightarrow 10 - 4}$

${\tt \longrightarrow \sf Rs \tt \: \: 6}$

Now,

Rate of interest :-

${\tt \longrightarrow \dfrac{6 \times 100}{4 \times 50}}$

${\tt \longrightarrow \dfrac{6 \times \cancel{100}}{4 \times \cancel{50}} = \dfrac{6 \times 2}{4 \times 1}}$

${\tt \longrightarrow \cancel \dfrac{12}{4} = \boxed{\tt 3 \bf\%}}$

$\Huge\therefore$The rate of interest to the given sum is 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 :- ${\boxed{\tt\dfrac{SI \times 100}{P \times R}}}$

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More to know..................

• Simple Interest is the extra amount to be given when a person borrows some money from a person or a bank. The person who gives money is called lender. The person who takes money is called borrower.
• Principal is the amount given at first from lender to borrower.
• Rate of interest is the extra amount to be given from borrower to lender. It is always written in percentage format.
• Time is given for the borrower to return back the given money with the given interest.