Question

Q.1. Mayan opened a Recurring deposited account in a bank and deposited ₹300 per month for 1 years. If he received ₹ 3678 at the time of maturity, find the rate of interest per annum​

Answer 1

Konichiwa! Here's your Answer

(sorry for answering late TwT)

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To Find :-

Rate of Interest per annum

Answer :-

4 %

Steps to how to solve the problem :-

Given,

Principle amount : ₹300

Time                     : 1 years = 12 months

Maturity Value     : 3678

(1st Method)

Step 1,

Find the Simple Interest using

Maturity Value = Principle Amount x Number of Months + Interest

⇒ M.V = P x n + I                                               (Substituting the given values)

⇒ 3678 = 300 x 12 + I

⇒ 3678 = 3600 + I

∴ Interest = 3678 - 3600

                = ₹78

Step 2,

Find the rate of interest using the formula of interest

⇒ $I = P *\frac{n(n+1)}{2 * 12} + \frac{r}{100}$

⇒ 78       =  $300 * \frac{12 * 13}{2 * 12} * \frac{r}{100}$

⇒ 78       = 3 x $\frac{13}{2}$ x r

⇒ 78 x 2 = 3 x 13 x r

⇒ 156     = 39r

∴ r = 4%

Thus, The rate of interest per annum is 4%

The other method is directly using the formula

⇒ $P * n + P * \frac{n(n+1)}{2 * 12} * \frac{r}{100}$

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I hope you understood mate!!

Sayonara~

Answer 2

Given:

Mayan opened a Recurring deposited account in a bank and deposited ₹300 per month for 1 years.

If he received ₹ 3678 at the time of maturity.

To Find :-

Rate of Interest per annum  

Given,

Principle amount : ₹300

Time                     : 1 years = 12 months

Maturity Value     : 3678

(1st Method)

Step 1,

Find the Simple Interest using

Maturity Value = Principle Amount x Number of Months + Interest

⇒ M.V = P x n + I                                               (Substituting the given values)

⇒ $3678 = 300 *12 + I$

⇒ $3678 = 3600 + I$

∴ Interest $= 3678 - 3600 = 78$rs

Step 2,

Find the rate of interest using the formula of interest

⇒ $I=P*\frac{n(n+1)}{2*12} +\frac{r}{100}$

⇒ $78=300*\frac{12*13}{2*12} *\frac{r}{100}$

⇒$78 = 3 * \frac{13}{2} * r$

⇒ $78 * 2 = 3 * 13 * r$

⇒$156 = 39r$

∴ $r = 4%$

Hence, The rate of interest per annum is 4%