What is the $($effective$)$ interest rate in each of the following cases.

Bought a bond with a face value of $$10,000,$ held it for six months and received a coupon payment of

$$315($a$)\_\_\_\_\_\_\_\_\_\_\%$

Borrowed $895,000,000$ on June $12024$ and repaid $1,000,000,000$ on June $1,2027$ :$($b$)\_\_\_\_\_\_\_\_$

All answers are to be rounded to three decimal places.