Let's use a simpler representation with the relationships.
Let region a be students only in H.
Let region b be students only in S.
Let region c be students only in A.
Let region d be students in H and S only.
Let region e be students in H and A only.
Let region f be students in S and A only.
Let region g be students in H, S, and A.
From the problem statement:
n(H)=a+d+e+g=5x
n(S)=b+d+f+g=6x
n(A)=c+e+f+g=11x
Every student is in at least one group: a+b+c+d+e+f+g=N total
From Statement (1): All students enrolled in Hiking are also enrolled in Archery (H⊆A).
This means:
a=0 (no one is only in H).
d=0 (no one is in H and S but not A). This is because if d>0, then there are students in H and S but not A. If H⊆A, then any student in H must be in A. So, if they are in H and S, they must also be in A. So d must be 0.
So, n(H)=e+g=5x.
From Statement (2): Every student enrolled in Archery is also enrolled in at least one other group.
This means no student is only in Archery.
So, c=0.
Now combine (1) and (2):
a=0
d=0
c=0
Let's rewrite the initial equations with these zeroes:
n(H)=e+g=5x
n(S)=b+f+g=6x
n(A)=e+f+g=11x
We need to find
n(S∩A)/ n(A) = f+g/ (e+f+g)
From n(A)=e+f+g=11x.
We have e+g=5x.
Substitute this into the equation for n(A):
n(A)=(e+g)+f=11x
5x+f=11x
f=6x
Now we have f=6x.
We need to find
f+g / 11x
We still need g.
Let's use the total number of students. "Every student is enrolled in at least one of these groups."
N total =a+b+c+d+e+f+g.
With a=0,c=0,d=0:
N total =b+e+f+g.
We know e+g=5x and f=6x.
So, N total=b+5x+6x=b+11x.
We also know n(S)=b+f+g=6x.
Substitute f=6x:
b+6x+g=6x
This implies b+g=0. Since b and g represent counts of students, they must be non-negative.
Therefore, b=0 and g=0.
Now we have:
a=0
b=0
c=0
d=0
g=0
Let's check consistency:
n(H)=e+g=e+0=e=5x.
n(S)=b+f+g=0+f+0=f=6x.
n(A)=c+e+f+g=0+e+f+0=e+f=11x.
Is e+f=5x+6x=11x? Yes, it is consistent.
So, the only non-zero regions are e (Hiking and Archery only) and f (Swimming and Archery only).
This means:
Students in Hiking are only in Hiking and Archery (e).
Students in Swimming are only in Swimming and Archery (f).
No student is in all three groups (g=0).
No student is only in one group (a=0,b=0,c=0).
No student is in Hiking and Swimming only (d=0).
The question asks for the fraction of students enrolled in Archery who are also enrolled in Swimming.
This is
n(S∩A)/n(A)
n(S∩A)=f+g. Since g=0, n(S∩A)=f.
n(A)=e+f+g. Since g=0, n(A)=e+f.
So we need to find f/ (e+f)
We found f=6x and e=5x.
Therefore, the fraction is
6x / (5x+6x) = 6x/11x = 6/11
This means that combining both statements is sufficient to answer the question.
Final answer is C