A fresh apple is 80% water and 5% sugar, so when the apple is drained, the proportion of water is 20%. What's the sugar content of this apple?

Faced with this percentage problem, let's assume that the weight of apples is1g.

Solution:

Suppose the apple weighs 1g, then we have the weight of other things.

1*0.2=0.2g

Now we can calculate the weight of dried apples.

0.2/0.8 = 0.25g.

The weight of sugar is a constant, so

0.05 ÷ 0.25 =20%

The water content of apples has changed, but other substances have not changed. Grasp this and you can get 20% of the answer.