The blood that circulates in our body is about 1/12 of our mass. If the kidneys filter 7.5 liter of blood a hour, then how many times does it filter in the kidney the whole blood of a person will mass 60kg? Here's what my teacher did: 1/12*60=5 liter blood 0.55*5=2.75 liter plasma of blood. The plasma is filtered 60 times is 24 hours. (how did she find that?) 24 hours ->60 times the plasma filters 1 hour -> x x=2.5 times Do you understand her explanation? What should I do next?