The sum of an odd number of odd numbers will always be odd , since it is not possible to say 50 or even. However, if the answer is as follows: Roman 3 + 13 + 7 + 15 + 1 = 50 , that is , 1 + 3 + 7 + 13 + 15 = 3 + 13 + 7 + 15 + 1 = III + XIII + VII + XV + I = II (I + XI + V) + XV + I = 2 (1 + 11 + 5) + 15 + 1 = 2 (17) +16 = 34 + 16 = 50