Please help with epidemiology homework and explain

3. One hundred and eighty panama were treated for a disease from 2007 to 2009, and their progress was followed to 2010. Three treatment results are given in the table below. No patients were lost to follow-up. Nmnber of Patits Treated \"-- mm- lil- m - m--- __ 152 What' Is the probability of surviving two years? b. Suppose there are 100 men expected to survive with the absence of disease and actually 85 of them survive. Calculate the relative survival [fraction]