What have you tried? Your interest rate is not defined very well. This leaves the problem statement open to various interpretations. Shall we assume monthly compounding?

Let's say the MONTHLY effective rate is 'i' and r = 1+i

Then:

Solve for 'i' and then maybe convert to ANNUAL EFFECTIVE or ANNUAL NOMINAL or whatever it is you think the question wants.

Hint: if that helps.

Show you work. So far, I've seen nothing.