If the federal reserve sells 40000 in treasury bonds to a bank at 5 interest what is the immedate effect on the money suppy?

When the Federal Reserve sells $40,000 in Treasury bonds to a bank, it decreases the money supply by that amount. The bank pays for the bonds using its reserves, which reduces the reserves available for lending. Consequently, this action tightens the money supply, as there is less money available in the banking system for loans and other transactions. The interest rate of 5% is relevant for future borrowing but does not directly affect the immediate change in the money supply from this transaction.