Question 852401
You kept the question completely open.  The question is most likely, what mixture is best?


Only the fictional campers would know that.  They would have tried tasting and /or drinking a little of some of the mixtures and made their decision.


Make their mixture list neater!

Mixture__________Concentrate_____Water_____%parts conc.
A________________2_______________3_________40
B________________1_______________4_________20
C________________1_______________2_________67
D________________3_______________5_________37.5


Notice two things:
(*)  Mix C is in lowest terms instead of as described.
(*)  The highest concentration mixture is C;
(*)  The lowest concentration mixture is B.


More interesting information if were given would be, how much juice concentration is in  stock, and how much the two campers use to make test blends.