Question

The simple interest on a principal for 2 years at 10% p.a. is Rs. 1700. Find the principal amount.

chapter : compound interest 9th
pls help fast​

Answer 1

Direct Answer:

Rs.8500

Given:

Rate of Interest [R] = 10% p.a.

Time period [T] = 2 years

Simple Interest [SI] = Rs.1700

To Find:

The principal amount [P].

Solution:

Here, we have to implement the concept of simple interest to find the principal amount on which the given simple interest is levied. The formula to be used is:

$\tt{\implies\:Simple\:Interest=\dfrac{P\times\:R\times\:T}{100}}$

Here, we know the values of R, T and SI. Implementing these values into the equation,

$\sf{\longrightarrow\:1700=\dfrac{P\times10\times2}{100}}$

$\sf{\longrightarrow\:1700=\dfrac{P\times1\times2}{10}}$

$\sf{\longrightarrow\:1700=\dfrac{P}{5}}$

$\sf{\longrightarrow\:P=1700\times5}$

$\sf{\longrightarrow\:P=8500}$

Therefore the principal amount is Rs.8500.

Verification:

If we substitute the value of P into the LHS of the equation and obtain the simple interest as provided in the question, our answer is correct.

LHS:

$\sf{\implies\:\dfrac{P\times\:R\times\:T}{100}}$

$\sf{\longrightarrow\:\dfrac{8500\times10\times2}{100}}$

$\sf{\longrightarrow\:85\times20}$

$\sf{\longrightarrow\:1700}$

RHS:

$\sf{\implies\:1700}$

LHS = RHS

Hence verified!

Answer 2

$\mathfrak{Solution-:}$

Given-:

• Principal (P) = Rs. 1700
• Rate (R) = 10% p.a.
• Time (T) = 2 years

To Find-:

• Principal Amount = ?

Using Formula-:

$\bigstar \:  \underline{ \boxed{ \tt  {S.I \:  = \:   \frac{P × R × T}{100} } \\  \\ }}$

where,

• P denotes Principal
• R denotes Rate
• T denotes Time

Calculation-:

$\bigstar \:  \underline{ \boxed{ \tt  {S.I \:  = \:   \frac{P × R × T}{100} } \\  \\ }} \\ \\ \sf \implies \: 1700 \: = \: \frac{P \: \times \: 1 \cancel{0} \: \times \: {2 }\: }{ 10 \cancel{0} } \\ \\ \sf \implies \: 1700 \: = \: \frac{P \times \cancel{ 2}}{ \cancel{1 0} \: 5} \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \\ \\ \sf \implies \: 1700 = \frac{P}{5} \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \\ \\ \sf \implies \: P \: = \: 1700 \times 5 \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \\ \\ \boxed{ \sf \implies \: Rs. \: 8500} \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \:$

Hence, Principal Amount = Rs. 8500.

$\rule{200pt}{4pt}$

MORE TO KNOW-:

★ Principal-: The money you borrow is known as Principal.

★ Interest-: For keeping the money for sometime the borrower has to pay some extra money which is known as Interest.

★ Time Period-: The Period for which the money is borrowed is known as Time Period.

★ Amount-: Total money paid by the borrower to the lender is known as Amount.

• Amount = Principal + Interest

★ Rate of Interest is generally given in percent per year.

★ Simple Interest-: If the Principal remains the same for the entire loan period, then the Interest paid is called Simple Interest (S.I).