1, 18, 12, 15, 5, 13, 17, 4, 8, 18

(a)  

5, 13,17,4, 8, 18, 9, 7, 12, 13

(a)  

15, 7, 5, 13, 9, 7, 12, 13

(a)  

20, 5, 2, 15, 15, 1, 2, 16, 6, 13, 2, 19, 7, 5

(a)  

17, 19, 21, 19, 18, 8, 17, 5

(a)