Solution to: The Cucumber Case
In the morning, the 200 kilograms of cucumbers are 99% water. Therefore, the non-water part of the cucumbers has a mass of 2 kilograms. At the end of the day, the cucumbers are 98% water. The remaining 2% is still the 2 kilograms of non-water material (which does not change when the water evaporates). If 2% equals 2 kilograms, then 100% equals 100 kilograms. Consequently, the greengrocer has 100 kilograms of cucumbers left at the end of the day.