Althea + Leah + Jessika = 34, (L+5) + L + (L-4) = 34, ====> 3L + 1 = 34 ====> 3L = 34 - 1 = 35 ====> L = = 11. Answer. Leah is 11 years old. Althea is 11+5 = 16 years old. Jessika is 11-4 = 7 years old.