Barney is aged 55 and Hilda is aged 65. An annuity of A' per month at the beginning of each month is payable to Barney for life. If Barney dies before Hilda, a reversionary annuity of Jf — 100 per month will continue to Hilda for life. The net single premium for this annuity is 50,000. Find X given 4f=12,C» = 8.5andC>3 = 7.2.