Question

Question
What sum of money at compound interest will amount to Rs. 6930 in 3 years, if the rate of interest is 5% for
the first year, 10% for the second year and 20% for the third year?
26​

Answer 1

Answer:

5000

Step-by-step explanation:

Amount = principal (1+R1/100)*(1+R2/100)*(1+R3/100).

6930= principal(110/100)*(105/100)*(120/100).

principal=(6930*1000)/1386

principal=5000

Answer 2

Given :

Amount (A) = 6930

 Time( n ) = 3 years.

R =  5 % , 10 % , 20% for 1 year, 2nd year and 3rd year respectively.

To Find :

Principle (P) = ?

Solution :

We know that the Amount for n years = P $(1 + \frac{R}{100} )^{n}$

Amount = P ( 1 + $\frac{5}{100}$) ( 1 + $\frac{10}{100}$) ( 1 + $\frac{20}{100}$)

6930 = P ( $\frac{105}{100}$) ($\frac{110}{100}$) ( $\frac{120}{100}$) [ A= 6930 given]

6930 = P ( 1386000/1000000)

6930 = P ( 1.386)  

P = 6930/ 1.386 = 5000

So, the principle amount = Rs. 5000

∴ Rs. 5000 at compound interest will amount to Rs. 6930 in 3 years, if the rate of interest is 5% for  the first year, 10% for the second year and 20% for the third year.