100 kg of potatoes, 99% water. leave them out overnight. now they're 98% water. how much do they weigh?
100 kg
water content99%
100.0 kg
dry matter1.0 kg
water99.0 kg
the dry matter never changes. at 98% water, that 1 kg is 2% of the total — so the whole thing halves. the intuitive answer ("loses 1% of its water, ~99 kg") is off by almost half.