1. (16 points) Fresh mushrooms contain $90 \%$ water by mass, while dried mushrooms contain $12 \%$ water. How many kg of dried mushrooms can be obtained from 22 kg of fresh mushrooms?
# Answer: 2.5 kg

Solution. The dry matter in fresh mushrooms is 2.2 kg, which constitutes $88\%$ of the weight in dried mushrooms. By setting up the corresponding proportion, we will find the weight of the dried mushrooms.