Multiple choice What is the life span of red blood cells in the blood stream? 120 days 5 to 20 days 2 to 3 days 5.4 days 6 to 16 days Reveal answer Fill a bubble to check yourself A Correct answer Explanation RBCs last an average of 120 days in the bloodstream. When RBCs get aged, they are removed by macrophages in the liver and spleen.