What is the inerest rate if the government perpetuity pays 4 a year and is selling for 48?

What is the inerest rate if the government perpetuity pays 4 a year and is selling for 48?
The interest rate is 8 1/3 because Present Value = Payment/Interest rate
Present Value = 48
Payment is 4
Interest Rate = Payment/Present Value = 4/48 = 8.33%