If science and technology books are regarded as five and comics as two, then comics are less than science and technology books by three.

So the number of copies of 1 is 90÷3=30.

So the number of science and technology books is 30×5 = 150, and the number of comic books is 30×2 = 60.

A: There are 60 comic books and 50 science books/kloc-0.