Converting all values to decimal, we have
1/5 = 0.2
19% - 19/100 = 0.19
Therefore the snack that contains 19% has the least amount of calories from fat.
Seems to be that the limit to compute is

Consider an arbitrary line through the origin

, so that we rewrite the above as

The value of the limit then depends on the slope

of the line chosen, which means the limit is path-dependent and thus does not exist.
Emma’s age is 26 and her sister is 15 because 26 - 15 = 11 (The age that Emma is older by) and once you add 26 and 15, it equals 41
I would say that the unfinished puzzle has more than one piece and the missing piece is only one, itself.