1. Nine ways: 2 X $20; 1 X $20, 2 X $10; 1 X $20, 1 X $10, 2 X $5; 1 X $20, 4 X $5; 4 X $10; 3 X $10, 2 X $5; 2 X $10, 4 X $5; 1 X $10, 6 X $5; 8 X $5
2. Sixteen ways
3. The cube
4. Queen-1; King-7; Pawn-5; Knight-4; Bishop-2
5. (a) 6 snakes, (b) 14 lizards, (c) 7 people
6. 72 metres
7. Four ducks
8. 11 times
9. (a) 13; (b) 1 in 144 or 1:143
10. Alice is 10, Bill is 5, Charlie is 9