Jill sold half of her comic books and then bought 16 more. She now has 36. With how many did she begin?
The answer is 40
Start with 40 comic books. Divide in half is 20. Add 16 and you get 36. Try working backwards on these. Like 36-16 is 20...
40 comic books.
Let's say she started with x comic books:
then she bought 16 more:
now she has 36 comics: