Mathematical problems, shopping and distribution?

Suppose: buy X bear dolls and Y toy cars.

108x+72y=2500 (where x and y are integers).

y=(2500- 108x)/72

When x= 1 (Taiwan), y=33 (Taiwan) * * * Consumption: 2484 yuan.

When x=3 (Taiwan), y=30 (Taiwan) * * * Consumption: 2484 yuan.

When x=5 (Taiwan), y=27 (Taiwan) * * * Consumption: 2484 yuan.

When x=7 (Taiwan), y=24 (Taiwan) * * * Consumption: 2484 yuan.

When x=9 (unit), y=2 1 (unit) * * * Consumption: 2484.

When x= 1 1 (Taiwan), y= 18 (Taiwan) * * * Consumption: 2484 yuan.

When x= 13 (Taiwan), y= 15 (Taiwan) * * * Consumption: 2484 yuan.

When x= 15 (Taiwan), y= 12 (Taiwan) * * * Consumption: 2484 yuan.

When x= 17 (Taiwan), y=9 (Taiwan) * * * Consumption: 2484 yuan.

When x= 19 (Taiwan), y=6 (Taiwan) * * * Consumption: 2484 yuan.

When x=2 1 (Taiwan), y=3 (Taiwan) * * * Consumption: 2484 yuan.

When x=23 (Taiwan), y=0 (Taiwan) * * * Consumption: 2484 yuan.

Summary: y=(2484- 108x)/72. . . (16 yuan)