Answer:

40 comic books
Explanation:
Let x be the Jill comic books.
Given:
Jill sold half of her comic books and then bought sixteen more. She now has 36.



Therefore the algebraic equation of the given statement.
--------(1)
Now we solve above equation for x.
Subtract by 16 both side of the equation 1.


Multiply by 2 both side of the above equation.


Therefore, Jill had 40 comic books.