Question: http://www.actuariesindia.org/downloads/exampapers/mar2017/Q_CT4.pdf Solution: http://www.actuariesindia.org/downloads/exampapers/mar2017/SOL/CT4.pdf In question no. 2 (ii), solution shows that the integration is done between age 0 to 60 to to find the probability of a person aged 30 days surviving till age 90 days. My confusion is, should not it be done from 30 to 90 as the mortality rate changes with time (given u = -0.5 + lambda t ) ? What am I missing?
The u subscript is x+30 representing the age - So if x+30 = 30 then x is 0, if x+30=90 then x is 60. So you integrate between 0 and 60 (for integrating between age 30 to 90)