Okay I am terrible at math. Can someone please break down this math better than the explanation? How they solved this without calculator. Possibly anyway you thought of this problem. In the passage the equation I/I0=e^-uk and it was stated that anything less than 1%of incidence radiation transmission was considered safe.
![Screenshot (103).png]( "Screenshot (103).png")
![Screenshot (103).png]( "Screenshot (103).png")
