# Boat and stone - science puzzle

Suppose you sit in a rubber boat in a swimming pool. In the boat lies a stone. You throw this stone from the boat into the pool. Will the water level in the pool raise or drop?

# Boiling an egg - logic puzzle

Suppose you would like to boil an egg for exactly 15 minutes. But you only have two hourglasses, one of zeven and one of eleven minutes. What is the the fastest way to do this? |

# Cucumbers - math puzzle

In the morning a green-grocer puts 200 kg cucumbers outside in front of his shop. These cucumbers consists for 99% out of water. Because it is a warm day some water will evaporate. As a result, at the end of the day the cucumbers consist for 98% out of water. How many kg's of these cucumbers are left at the end of the day? |