Hi all,
i am preparing for Exam P/1.I am having difficulty with following problem :

Under an insurance policy, a maximum of five claims may be filed per year
by a policyholder. Let Pn be the probability that a policyholder files n claims
during a given year, where n = 0; 1; 2; 3; 4; 5: An actuary makes the following
observations:
(i) pn >= pn+1 for 0 <= n <= 4
(ii) The difference between pn and pn+1 is the same for 0 <= n <= 4
(iii) Exactly 40% of policyholders file fewer than two claims during a given
year.
Calculate the probability that a random policyholder will file more than three
claims during a given year.


Thanks in advance!!!!!!!