1. Alex is 10, Bill is 5, Charlie is 9

2. Losing
(eg start with $1000. It will decrease to $900, then increase to $990)

3. $8.70

4. 15

5. 150 km

6. Shape d. Shapes a, b and c are rotations of each other; d is a non-superimposable mirror image.

7. 500 litres (actually about 524)

8. 4 cubes

9. 8

10. 24 minutes