Answer:
2
Step-by-step explanation:
there is 2: 3<u> 1 </u>
4
Answer:

Step-by-step explanation:
Given,
Art electives = 3,
History electives = 4,
Computer electives = 5,
Total number of electives = 3 + 4 + 5 = 12,
Since, if a student chooses an art elective and a history elective,
So, the total combination of choosing an art elective and a history elective = 
Also, the total combination of choosing any 2 subjects out of 12 subjects = 
Hence, the probability that a student chooses an art elective and a history elective = 

Which is the required expression.