SQL/ACCESS

Please help me with a solution

DESIGN A QUERY TO RETURN THE VALUE AGGREGATE:
a student takes 3 core subject and 2 optional subject. calculate aggregate of each student given that: Aggregate is calculated out of 4 subjects, i.e: all 3 core subject one high optional subject.

LOOK AT THIS SAMPLE DATA
student name , subject1 , subject2 , subject3 , option1 , option2 , AGGREGATE
raymond , 4 , 7 , 4 , 8 , 7 , 23
donald , 5 , 2 , 7 , 2 , 4 , 18
richard , 4 , 6 , 3 , 1 , 1 , 14