For a special 20-year temporary life annuity-due payable monthly on (50), you are given:

Mortality follows the Illustrative Life Table with = 0.06.

Deaths are uniformly distributed over each year of age.

100 is payable at the beginning of each month from age 50 for 10 years.

400 is payable at the beginning of each month from age 60 for 10 years.

Calculate the expected present value of these annuity payments.