Can some one help me with this coding midterm

Arla made a spreadsheet in excel showing the projected costs for a concert she was putting on. what can marla enter into cell a11 to find out how much money is left in her budget and to make sure the cell is updated whenever she changes any of the other costs?

Asuccessful format string attack attempted to steal user account information by reading from unauthorized memory. answer the followings with proper explanation a)this attack will lead to violation of which security policies?

Larry sent an email to andy. andy didn't open larry's email but still understood what the message was. how did andy determine the message without opening the email?