Leslie selects an optional pension benefit which entitles her to monthly payments ofX, beginning at age 60, for 10 years certain and thereafter as long as Leslie and her spouse are both alive.

Leslie is 5 years older than her spouse. The normal pension benefit at the time of retirement is a single-life annuity of 1 ,000 per month. Find X under the optional form, given / = .09, Deo = 280, D55.6O = 900, N^l^^ = 2500 and 7V^5^4 = 2800.