$1.$What is the value of $15-$year corporate bonds, with an annual coupon rate of $9\%$ and semi$-$annual payments, if the yield on similar bonds is $8\%$ per year? How much would the value change if the yield increased to $10\%$ per year? Under what conditions will this bond trade at par $($face value$)?$

$2.$ Explain the difference between Uniform Auction and Discriminatory Auction.