Question

If Rihanna deposits 1500 rupees in the school fund at 9% per annum for 2 years. What is the total amount she will get our 2 years?

Answer 1

Hint: Rihanna deposited Rs 1500 calculating the total interest she will get after 2 years. Now add the amount she deported to the total interest value to get the amount she will receive after 2 years.

Complete step by step solution: We will solve this problem by applying the very basic simple interest formula
It is given that Rihanna deposited Rs 1500 in the school fund.

∴ The principal amount = Rs 1500

i.e. P = Rs 1500
Given that,
     Rate of interest = 9 % per annum
Time period = 2 years
     T = 2 years

Now we will calculate the total interest Rihanna will get after 2 years using a simple interest formula.

i.e. Total interest after 2 years

$ = \dfrac{{{\text{PRT}}}}{{{\text{100}}}}$
$ = {\text{Rs}}\dfrac{{1500 \times 9 \times 2}}{{100}} = {\text{Rs}}\;270$

∴ The total interest she will receive after two years is Rs. 270.

∴ The total amount she will receive after two years

= Principal amount + Total interest
= Rs 1500 + Rs 270
= Rs 1770

∴ Total amount Rihanna will get after 2 years is Rs 1770.

Note: We can solve it without using the formula also. Here is the procedure :
Amount deposited = Rs 1500 at 9% per annum interest
⇒ Interest at the end of the first year = Rs $1500 \times \dfrac{9}{{100}}$
                         = Rs 135
Interest at the end of 2nd year = Rs 135 + Rs 135
                    = Rs 270
∴ Total amount she will receive after 2 year is Rs 1500 + Rs 270 = Rs 1770.