If riley had 6/5 of a cake and rico had 3/5, kiley had how much cake? (not subtraction or adding) (show work)

Unless there is more than one cake, Riley could not have eaten 6/5 of a cake, as 6/5 is the same as 1 and 1/5, implying that Riley ate the whole cake, and then at another 1/5 of the cake that he had already eaten.