9. Leilei went to buy instant noodles and handed the boss a 100 yuan note. After giving her the change, the boss said to her: "You only gave me 1 piece of money, but I gave you 16 pieces of money, plus instant noodles worth 5 yuan, you really got a great deal!" If the money the boss gave Leilei was either 10 yuan or 5 yuan notes, then among these 16 pieces of money, $\qquad$ pieces are 10 yuan notes.
【Analysis】16 banknotes, the total price is 95 yuan. Assuming all are 5 yuan, then the total face value is 80 yuan, which is 15 yuan short. Below is the replacement: replace 1 5-yuan note with 1 10-yuan note, the face value increases by 5 yuan, and we need to replace 3 notes. Therefore, among the 16 banknotes, there are 3 10-yuan notes.