Can someone please explain how they arrive at the answer? Thanks in advance.

If notreatment has been given within 3 hours after injury to a certain organ, theorgan’s function starts decreasing by 20% each hour. If no treatment has beengiven with 6 hours after injury, approximately how much function will remain?

Answer

At theend of three hours, the organ still has 100% function.

After 4hours, it has 80% of that 100%, or (0.8)(1), or 0.8.

After 5hours, it has 80% of the 80% it had at the end of four hours: (0.8)(.8) equals64%.

After 6hours, it has 80% of the 64% it still had after five hours: (0.8)(0.64) equals 0.512.

Can youplease explain why 80% is constant after 4 hours not decreasing anadditional 20%?