David Gwyn J. answered 10/16/20
Highly Experienced Tutor (Oxbridge graduate and former tech CEO)
Let W be campers doing water-based activities, and let S be campers doing sports activities.
Part A:
W >= 8
S >= 5
W + S <= 80
You can combine these inequalities and say that: 8 <= W <=75 AND 5 <= S <= 72. Which means there are MANY possible valid arrangements/quantities of campers.
Part C:
The smallest camp size is 13 campers with 8 in the water, and 5 doing sports.
or
The largest camp size is 80 campers, and we could, if we choose, divide them equally with 40 in the water and 40 doing sports.
or...