This question is easy. It would be a real piece-o-cake if we knew ...
-- How many rolls are there is a package of 36-exposure film ?
-- How many rolls are there in a pack of 24-exposure film ?
-- How many rolls did Hannah use, lose, or give away ?
Without knowing any of these things, this is a real puzzler.
In fact, it can't be answered with only the given information.
