title: Blood
context: Blood accounts for 7% of the human body weight,[3][4] with an average density around 1060kg/m3, very close to pure water's density of 1000kg/m3.[5] The average adult has a blood volume of roughly 5 litres (11USpt),[4] which is composed of plasma and several kinds of cells. These blood cells (which are also called corpuscles or "formed elements") consist of erythrocytes (red blood cells, RBCs), leukocytes (white blood cells), and thrombocytes (platelets). By volume, the red blood cells constitute about 45% of whole blood, the plasma about 54.3%, and white cells about 0.7%.
question: How much blood is in the human body?
answers: Blood accounts for 7% of the human body weight