Answer: The monthly interest rate is 1.67%.
Step-by-step explanation: To find the monthly interest rate, we need to divide the yearly interest rate by the number of months in a year. Since there are 12 months in a year, we can divide the yearly interest rate by 12 to get the monthly interest rate.
The monthly interest rate can be calculated as:
Monthly interest rate = Yearly interest rate / 12
In this case, the yearly interest rate is 20%. So, the monthly interest rate can be calculated as:
Monthly interest rate = 20% / 12 = 1.67%
Therefore, the monthly interest rate is 1.67%.