Simple Interest on Rs.800 in 3 years at 4% , equals twice the interest on Rs.300 at 8% in 'n' years,then find 'n'.

Interest on Rs. 800 for 3 years at 4% is equal to twice the interest on Rs. 300 at 8% for n years.

The formula for Simple Interest (SI) is:

​$$SI = \frac{P \times R \times T}{100}$$​​

Where:

P is the principal,

R is the rate of interest,

T is the time in years. 

Solution: ​

According to the question,

​$$\frac{800 \times 3 \times 4 }{100} = 2 \left( \frac{300\times 8 \times n}{100}\right) \\ \ \\ 800 \times 12 = 300 \times 16 \times n \\ \ \\ n = \frac{ 800 \times 12 }{ 300 \times 16} \\ \ \\ n = 2 \text{years}$$