Question

in a class of 60 student, the number of student who passed biology is 6 more than the number of student who passed chemistry. Every student passed at least one of the two subject and 8 student passed both subject.
1)how many student passed biology?
2)how many student passed chemistry?
3)how many student passed only one subject

Answer 1

If b passed biology, and c passed chemistry, you know that
b+c-8 = 60
b = c+6
See what you can do with that.