Tag: introduction to interests

Questions Related to introduction to interests

Oscar earned Rs. $2400$ as simple interest on Rs. `$4500$ for $3$ months. What is the annual rate of interest?

  1. $16.66\%$

  2. $17.77\%$

  3. $18.88\%$

  4. $19.99\%$


Correct Option: B
Explanation:
Given, principal $=4500$, Interest $=$ Rs. $2400$, period $=3$ months
We know the formula,
Rate of interest, $R =$ $\dfrac{I\times 100}{PT}$
$\Rightarrow R =$ $\dfrac{2400\times 100}{4500\times 3}$
$\Rightarrow R = 17.77\%$
Therefore, the annual rate of interest is $17.77\%$.

To start a grocery shop, a woman borrowed Rs. $1,500$. If the loan was for four years and the amount of interest was Rs. $150$, what simple interest rate was she charged?

  1. $1.5\%$

  2. $2.5\%$

  3. $3.5\%$

  4. $4.5\%$


Correct Option: B
Explanation:
Given, principal $=$ Rs. $1500$, Interest $=$ Rs. $150$, period $=4$ years
We know the formula,
Rate of interest, $R =$ $\dfrac{I\times 100}{PT}$
$\Rightarrow R =$ $\dfrac{150\times 100}{1500\times 4}$
$\Rightarrow R = 2.5\%$
Therefore, the simple interest is $2.5\%$.

Mr. Joshua borrowed Rs. $5000$ for $2$ years to make home improvements. If he repaid a total of Rs. $15,000$, at what interest rate did he borrow the money?

  1. $15\%$

  2. $25\%$

  3. $35\%$

  4. $45\%$


Correct Option: B
Explanation:

Given:
Principal $= 5,000$
Interest $= 15000 - 5000 = 10000$
We know the formula,
Rate of interest, $R =$ $\dfrac{I\times 100}{PT}$
$\Rightarrow R =$ $\dfrac{5000\times 100}{10000\times 2}$
$\Rightarrow R = 25\%$

Peter invests $ $5,000$ at $4$% simple annual interest. How much in his investment worth after $2$ months?

  1. 5323.66

  2. 5033.33

  3. 5066.33

  4. 5343.67


Correct Option: B
Explanation:

If the principal amount is $p$, annual interest is $r$ $\%$ then for simple interest after $n$ years the amount will be $p\left (1+\dfrac {nr}{100}\right)$.
Here $p=5000$, $n=\dfrac {1}{6}$, $r=4$ $\%$
So, the amount after $2$ months is $5000\left (1+\dfrac {2}{300}\right) = 5000\left (\dfrac {151}{150}\right) = 5033.33$

The difference between compound interest and simple interest on an amount of Rs. $15,000$ for $2$ years is Rs. $96$. What is the rate of interest per annum?

  1. $8$

  2. $10$

  3. $12$

  4. Cannot be determined

  5. None of these


Correct Option: A
Explanation:

$\left [15000\times \left (1 + \dfrac {R}{100}\right )^{2} - 15000\right ] - \left (\dfrac {15000\times R\times 2}{100}\right ) = 96$
$\Rightarrow 15000 \left [\left (1 + \dfrac {R}{100}\right )^{2} - 1 - \dfrac {2R}{100}\right ] = 96$
$\Rightarrow 15000 \left [\dfrac {(100 + R)^{2} - 10000 - (200\times R)}{10000}\right ] = 96$
$\Rightarrow R^{2} = \left (\dfrac {96\times 2}{3}\right ) = 64$
$\Rightarrow R = 8$.
$\therefore Rate = 8$%.

Ramesh borrowed $Rs \ 14000$ from a bank on simple interest for a period of $5$ years. He returned $Rs \ 6000$ to the bank at the end of three years and $Rs \ 10,900$ at the end of the five years and closed the account. Find the rate of interest per annum.

  1. $4 \%$

  2. $4.14 \%$

  3. $6 \%$

  4. $9 \%$


Correct Option: B
Explanation:

We have,

$P=Rs.\ 14000$

Ramesh returned $Rs.\ 6000$ to the bank at the end of $3$ years.

And returned $Rs.\ 10, 900$ to the bank at the end of $5$ years.

So, the total amount returned by Ramesh is $6000+10,900=Rs.\ 16, 900$

$T=5\ years$
$R=?$

We know that
$A-P=\dfrac{PRT}{100}$ 

So,

$16900-14000=\dfrac{14000\times R\times 5}{100}$ 

$2900=140\times R\times 5$ 

$R=4.14\%$

Hence, this is the answer.

Find the simple interest rate applied to a principal over $8$ years if the total interest paid equals the borrowed principal.

  1. $10\%$

  2. $20\%$

  3. $12.5\%$

  4. $15\%$


Correct Option: C
Explanation:

We have given that interest and principal are equal.

Let Rs. $x$ be the interest and principal.
Here $T=8$ years
We know $S.I.=\dfrac{P\times R\times T}{100}$
$\Rightarrow$ $x=\dfrac{x\times R\times 8}{100}$
$\Rightarrow$ $R=\dfrac{100}{8}=12.5\%$
Simple interest rate is $12.5\%$.

Find the simple interest rate applied to a principal over $5$ years if the total interest paid equals the borrowed principal.

  1. $10\%$

  2. $20\%$

  3. $30\%$

  4. $40\%$


Correct Option: B
Explanation:

We have given that interest and borrowed principal are same.

Let $x$ be the interest and borrowed principal.
We know $S.I.=\dfrac{P\times R\times T}{100}$
$\Rightarrow$ $x=\dfrac{x\times R\times 5}{100}$
$\therefore$ $R=\dfrac{100}{5}=20\%$

What is the simple interest rate applied to a principal over $2.5$ years if the total interest paid equals the borrowed principal?

  1. $20\%$ 

  2. $30\%$

  3. $40\%$

  4. $50\%$


Correct Option: C
Explanation:

We have given that interest and principal are equal.

Let Rs. $x$ be the interest and principal.
Here $T=2.5$ years
We know $S.I.=\dfrac{P\times R\times T}{100}$
$\Rightarrow$ $x=\dfrac{x\times R\times 2.5}{100}$
$\Rightarrow$ $R=\dfrac{100}{2.5}=40\%$
Therefore, simple interest rate is $40\%$.

Jenn borrowed Rs. $5,000$ for $5$ years and had to pay Rs. $1,500$ simple interest at the end of that time. What rate of interest did she pay?

  1. $5$

  2. $6$

  3. $7$

  4. $8$


Correct Option: B
Explanation:

$\Rightarrow$  $P=Rs.5000,\,T=5\,years $ and $S.I.=Rs.1500$

$\Rightarrow$  $S.I.=\dfrac{P\times R\times T}{100}$

$\Rightarrow$  $1500=\dfrac{5000\times R\times 5}{100}$

$\Rightarrow$  $R=\dfrac{1500}{250}$

$\therefore$    $R=6\%$