I don't know which formula to use. I could use some help

15 yrs Dr. Dahl saved $500.00 at the end of each month from age 40 to 55 earning 10% c.s.a. for his pension. The monies in his retirement account were then used to provide him with a monthly retirement cheque, for 25 years, the first cheque payable on his 65th birthday. Find the size of each monthly pension cheque using 10% c.s.a. throughout