The total number of students is N. We are given the following information:
Every student is enrolled in at least one of these groups: This means there are no students outside the three circles.
So, a + b + c + d + e + f + g = N.
For every 5 students in Hiking, there are 6 in Swimming and 11 in Archery.
H:S:A = 5:6:11
Let H = a+d+g+e=5k
S = b+d+g+f=6k
A = c+e+g+f=11k
We need to find the fraction of students enrolled in Archery who are also enrolled in Swimming.
i.e {S intersection A}/A
=(f+g)/(c+e+f+g)
Let's analyze the statements:
Statement (1): All students enrolled in Hiking are also enrolled in Archery. This means H is a subset of A. In terms of our regions, this implies:
a = 0 (No one is in Hiking only)
d = 0 (No one is in Hiking and Swimming but not Archery)
H = e + g = 5k.
From this statement alone, we still don't have enough information to determine (f+g)/(c+e+f+g)
Statement (2): Every student enrolled in Archery is also enrolled in at least one other group. This means there are no students in Archery only. In terms of our regions, this implies:
c = 0 (No one is in Archery only)
Let's analyze the statements combined.
Statements (1) and (2) combined: From (1): a = 0 and d = 0 From (2): c = 0
Now our equations become:
H = e + g = 5k
S = b + f + g = 6k (since d=0)
A = e + f + g = 11k (since c=0)
Substitute the first equation into the third:
A = (e + g) + f = 11k
5k + f = 11k
f = 6kWe also know that e + g = 5k.
And b + f + g = 6k.
Substitute f = 6k into the equation: b + 6k + g = 6k
==>b + g = 0
Since the number of students (b and g) cannot be negative, this implies: b = 0
g = 0Now since g = 0 ==>
e= 5kSo the required fraction is:
(f+g)/(e+f+g) = 6k/11k = 6/11
Both statements combined are sufficient Option C
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