A patient with severe trauma is being prepared for a massive transfusion protocol. The physician orders a total of 10 units of packed red blood cells (PRBCs), 10 units of fresh frozen plasma (FFP), and 5 units of platelets. The nurse must prepare to administer these blood products while remembering that the ratio of PRBCs to FFP should ideally be maintained at 1:1 in massive transfusion protocols to optimize coagulopathy management. Given this information, the total ratio of PRBCs to FFP administered must meet this standard, thus filling in the blank: ____ units of FFP are to be administered.