The concept: A 100-gram potato is 99% water. If it dries to become 98% water, it will weigh only 50 grams.
The Puzzlin’ Part explained:
We can explain this counter-intuitive result by using Algebra:
Let the lost weight =$$ x$$
We know that Weight of potatoes at 99% water – Weight of potatoes at 98% water = x
Substituting the weight of the potatoes, we get $$0.99(100) – 0.98(100 – x) = x$$
Simplifing this, we get:
$$99 – 98 + 0.98x = x$$
$$1 = x – 0.98x$$
$$1 = 0.02x$$
$$50 = x$$
Therefore, the total weight loss equals 50lbs. To determine the new weight, subtract the lost weight from the total weight at the beginning:
$$100-50 = 50$$
Therefore, the total final weight of the dehydrated potatoes is 50lbs