Question

Match the rate of interest for each of the Final amounts when ₹1000 is invested for 1 year in a bank.

• A. 8%
• B. 5%
• C. 18%
• D. 25%

Answer 1

You know,
Simple interest(SI) $=\frac{P\times R\times T}{100}$
where,
Principal amount invested = P
Rate of interest provided = R
Time period = T.

In first case,
Amount received at end of 1 year (A) = $₹1080$
∴ Interest amount:
= $A-P=₹1080-₹1000=₹80$

Now, find what percentage of $₹1000$ is $₹80$.
You can write this as:

Amount $\left(₹\right)$	Percentage $\left(\%\right)$
1000	100
80	?

= $\frac{100\times 80}{1000}$
= $8\%$

So, the rate of interest given by the bank will be $8\%$.

In second case,
Amount received at end of 1 year (A) = $₹1050$
∴ Interest amount:
= $A-P=₹1050-₹1000=₹50$

Now, find what percentage of $₹1000$ is $₹50$.
You can write this as:

Amount $\left(₹\right)$	Percentage $\left(\%\right)$
1000	100
50	?

= $\frac{100\times 50}{1000}$
= $5\%$

So, the rate of interest given by the bank will be $5\%$.

In third case,
Amount received at end of 1 year (A) = $₹1180$
∴ Interest Amount:
= $A-P=₹1180-₹1000=₹180$

Now, find what percentage of $₹1000$ is $₹180$.
You can write this as:

Amount $\left(₹\right)$	Percentage $\left(\%\right)$
1000	100
180	?

= $\frac{100\times 180}{1000}$
= $18\%$

So, the rate of interest given by the bank will be $18\%$.

And, finally, in case 4,
Amount received at end of 1 year (A) = $₹1250$
∴ Interest amount:
= $A-P=₹1250-₹1000=₹250$

Now, find what percentage of $₹1000$ is $₹250$.
You can write this as:

Amount $\left(₹\right)$	Percentage $\left(\%\right)$
1000	100
250	?

= $\frac{100\times 250}{1000}$
= $25\%$

So, the rate of interest given by the bank will be $25\%$.