I need help with part 3. Can you explain how for P4 the value for n is 16. I don't understand where that value comes from. Thank you!

1. Suppose you are considering buying a 10 year 5% bond that has a current price of 925.61 ? What yield to maturity can you expect from this investment? 2. Suppose the same bond (with the same current price and other characteristics) can be called in 5 years (it has a 5 -year call deferment) at a standard call premium of one coupon payment, which in this case would mean a call premium of $25. What yield to call can you expect from this bond? 3. Still considering the same bond, suppose you buy it today, but expect to sell it in two years at a yield to maturity of 4%. That is, you expect the yield to maturity on this bond to be 4% when you sell it in two years. What is your expected holding period yield