please solve it step by step without FM calculater

Martha leaves an estate of 100,000. Interest on this estate is paid to John for the first X years at the end of each year. Karen receives annual interest payments from the end of year X+1 forever. At an annual effective interest rate of 5.02%, the present value of Karen's interest payments is 1.25 times the present value of john's. Calculate X 8 9 10 11 12