Jill sold half of her comic books and then bought sixteen more. she now has 36. with how many did she begin with?

Is it asking how many she began with before she sold them? If so, then I think at the beginning she started out with 40. I think she had 40 because she sold half, and when you divide 40 by 2 it divides perfectly giving you 20. Then add 16 to that and you come out with 36. 

X= comic books 1/2 x+16=32 multiply by 2 to eliminate the fraction x+ 32=72 subtract 32 from both sides x= 40 Jill began with 40 books hope this helps