Answer:
The interest rate is 0.79% per month.
Step-by-step explanation:
Present value of borrowed amount = $350
Future value of borrowed amount = $400
Interest amount = $50
Time duration = 18 months or 1.5 years
Now we have to find the rate of interest by using the above information. Here below is the calculation of interest rate.
Interest rate = P×R×T
50 = 350 × R×18
R = 0.007936
Or, R = 0.79% per month.