The number of students who excelled in:
(a) All three subjects: 2
(b) Two subjects: 39
Let's denote the sets as follows:
S for the set of students excelling in Science
M for the set of students excelling in Mathematics
A for the set of students excelling in Arts
We are given the following information:
n(S∩M)=13
n(S∩A)=16
n(M∩A)=12
n(S∩M∩A)=2
n(none)=2
n(S∖(M∪A))=2 (Twice as many students excel in Science only as do in Mathematics only)
n(M∖(S∪A))=6 (The number of students who excel in Mathematics only is six times the number of students who excel in Arts only.)
Now, let's determine the number of students who excelled in each category:
(a) All three subjects:
n(S∩M∩A)=2
(b) Two subjects:
n(S∩M)+n(S∩A)+n(M∩A)−2n(S∩M∩A)=13+16+12−2(2)=39
So, the number of students who excelled in:
(a) All three subjects: 2
(b) Two subjects: 39