1. 5

2. c

3. E, D, C, B, A, G, F, H

4. (C) – as much water in the milk/water mixture as milk in the water/milk mixture

5. 50 kg: Most people assume the potatoes now weigh about 98 kg. But the potatoes now weigh just 50 kg! If you are wondering why, here is one way to look at it: Since 99% of the original 100 kg of potatoes is water, the remaining 1% (ie. 1 kg) of the original potatoes is actual potato “stuff”. Since the potato stuff doesn’t evaporate, it remains one kg. Now, after dehydration the potatoes are 98% water (which implies 2% of potato stuff). Since we know 2% of the potatoes (ie. the potato stuff) weigh one kg, 100% of the potatoes must weigh 50 times the weight of the potato stuff, which gives us 50 kg.

6. Beth is closest to the finish, followed by Emma, Carla, Alice, and Dianne.

7. 59

8. 30 km/h

9. 28

10. 2 ways