macroeconimics question

3. Assume that required reserve ratio is 20%, and that cash is not a part of the commercial banks' legal reserve [c = 0%}. a. To increase the money supply by $100, should the Fed buy or sell securities? __ And by hoyu.r much in the open market? _ b. To decrease the money supply by $200, could the Fed buy or sell securities? _____ By how much? ____