2 period interest rate?

I'm not sure exactly the context, as I don't think I have all the information. But here is a way to look at it which may help you to figure it out. At time period T1, you could go to the person who already owned a 3-year bond (he has 2 years remaining), and buy it. So the goal would be to figure what is a fair price. You need to know if it is simple interest or compound.

Simple interest is a little simpler to figure (imagine that), and I believe that is how most bonds work.

So the person who originally bought the $100 bond paying 10% for 3 years would get $10 per year. If you bought that from him, then to be fair, there would be an alternate bond which he could go and get the same $10 per year.

So he paid $100, he would want that back, and be able to purchase something else paying $10 per year for 2 years. Also he'd want to get the $10 due from the first year. So he might sell it to you for $110 and expect that he could invest that $110 into something which would pay $10 per year for 2 years. That would be 9.091% per year. Like I said, this is one way to think about the problem.