It is estimated that the total value of a stamp collection is given by the formula v=44,000+100t^2, where t is the number of years from now.

It is estimated that the total value of a stamp collection is given by the formula v=44,000+100t^2, where t is the number of years from now. If the inflation rate is running continuously at 4% per years so that the (discontinued) present value of an item will be worth $v in t years'time is given by p=ve^(-.04t). At what value of t is the present value increasing most rapidly?