.
Regarding the second student, from the condition we conclude that the remaining 0.3 lb represent
of his candies.
So,
of his candies is
= 0.15 lb; hence, the weight of his candies is 5 times 0.15 lb, i.e. 0.75 lb. ANSWER
Regarding the first student, the relevant info does not present a self-closed Math problem.
It requires additional assumptions from the outside of the given formulation.
So, strictly speaking, that part is not a Math style problem --- it is a Puzzle style, instead.