Final answer:
An average 155-pound person has about 5 to 6 liters of blood in their system, constituting around 8 percent of their body weight, with plasma being a major component.
Step-by-step explanation:
The average person weighing 155 pounds has approximately 5 to 6 liters of blood in their system. This estimate is based on the fact that blood constitutes about 8 percent of adult body weight.
Adult males usually have around 5 to 6 liters of blood, whereas adult females typically have 4 to 5 liters. A significant component of blood is plasma, which is mostly water and contains various proteins and other substances in suspension.