Final answer:
Jodi put 6 stamps in each book.
Step-by-step explanation:
To determine how many stamps Jodi has in each book, we need to follow the given steps:
1. Jodi bought 4 stamps on 3 different days, so she initially has 4 x 3 = 12 stamps.
2. She then bought 2 sets of 5 stamps, making a total of 2 x 5 = 10 stamps.
3. After buying the sets of stamps, she decided to sell 4 of them, leaving her with 12 + 10 - 4 = 18 stamps.
4. Finally, she divides the 18 stamps into 3 equal groups, so each book will have 18 / 3 = 6 stamps.
Therefore, Jodi put 6 stamps in each book.