Question

A principal of $750 becomes a total of $1320 in 8 years. What rate of
interest was being paid?
​

Answer 1

Answer:

P= $750

T=8 years

SI= $1320

R=?

SI=P×R×T/100

100×SI/P×T=R

R=132000÷(750×8)

R=22

therefore rate=22percent

Answer 2

➤ Correct Question :-

A principle of ₹750 becomes a total of ₹1320 in 8 years. What rate of interest was being paid ?

➤ Given :-

Principle :- ₹ 750

Total Amount :- ₹ 1320

Time :- 8 years

➤ To Find :-

Rate of interest to be paid at end...........

➤ 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 amount and principle..............

Simple Interest :-

$\tt \longrightarrow 1320 - 750$

$\tt \longrightarrow \sf Rs \tt \: \: 570$

Now,

Rate of interest :-

${\tt \longrightarrow \dfrac{570 \times 100}{750 \times 8}}$

${\tt \longrightarrow \dfrac{570 \times \cancel{100}}{ \cancel{750} \times 8} = \dfrac{570 \times 2}{15 \times 8} }$

${\tt \longrightarrow \dfrac{ \cancel{570} \times 2}{15 \times \cancel{8}} = \dfrac{285 \times 2}{15 \times 4}}$

${ \tt \longrightarrow \dfrac{570}{60} = \boxed{ \tt 9.5 \bf\%}}$

$\Huge\therefore$The rate of interest is 9.5 $\bf\%$.

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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 money from a bank or any person. The lender is a person who gives money. The borrower is a person who receives money.
• Principle is the amount given at first from lender to borrower or bank to a 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 money with the given interest.