2.0.5 yuan/rooster, 1 yuan/hen, 10 hen 10 yuan.
3. Rooster 10 1 9 yuan/Hen 20/ 19 yuan/Hen,10 yuan buys1rooster and 9 hens.
4.5 cocks /9 yuan/hens, 10/9 yuan/hens, 2 cocks and 8 hens 10 yuan.
5. Rooster 1017 yuan/Hen 20/ 17 yuan/Hen,10 yuan bought 3 roosters and 7 hens.
6. Rooster 5/8 yuan/Hen 5/4 yuan/Hen, 4 Roosters and 6 Hens 10 yuan.
7. Rooster 2/3 yuan/Hen 4/3 yuan/Hen, 5 Roosters and 5 Hens 10 yuan.
8.5 cocks /7 yuan/hens, 10/7 yuan/hens, 6 cocks and 4 hens 10 yuan.
9. Cock 1013 yuan/Hen 20/ 13 yuan/Hen, 7 cocks and 3 hens10 yuan.
10, cock 5/6 yuan/hen 5/3 yuan/hen, 8 cocks and 2 hens 10 yuan.
1 1, cock11/yuan/hen 20/1yuan/hen, 9 cocks 10 yuan.