The simple interest rate on a 1150$ investment paying 202.86$ interest in 3.6 years is 4.9%
Solution:
Given that
Amount invested = $1150
Interest earned on investment = $202.86
Duration of investment = 3.6 years.
Need to determine rate of interest
Let’s assume rate of interest in percentage be represented by variable "x"
Formula for Simple interest is as follows:

In our case simple interest = $202.86, principal = 1150 , rate of interest = x , duration = 3.6 years
On substituting the values in formula we get

On solving above expression for x, we get

Hence simple interest rate on a 1150$ investment paying 202.86$ interest in 3.6 years is 4.9%