3. If a schoolboy bought 11 notebooks, he would have 8 rubles left, but for 15 notebooks, he would be short of 12 rubles and 24 kopecks. How much money did the schoolboy have?
3. Let's represent the condition of the problem in a drawing:

![](https://cdn.mathpix.com/cropped/2024_05_21_e53d4ff4f2278a1c0d12g-071.jpg?height=486&width=1259&top_left_y=311&top_left_x=387)

1) $15-11=4$ (notebooks) - the difference in the number of notebooks purchased;
2) $800+1224=2024$ (kop.) - the cost of 4 notebooks;
3) $2024: 4=506$ (kop.) - the cost of one notebook;
4) $506 \times 11=5566$ (kop.) - the cost of 11 notebooks;
5) $5566+800=6366$ (kop.) $=63$ rubles 66 kop. - the amount the schoolboy had.

Answer: the schoolboy had 63 rubles 66 kop.