The weight of the grapes is 20 kg and the proportion of water is 90% of the total weight. As a result of drying out

The weight of the grapes is 20 kg and the proportion of water is 90% of the total weight. As a result of drying out, only 20% of the total mass began to come to its share. what is the final mass of raisins?

If the proportion of water in grapes is 90%, then the proportion of dry matter is:

100% – 90% = 10%.

The share of dry matter is 10%. Let’s find the mass of dry matter in 20 kg of grapes. Let’s make the proportion:

20 kg – 100%,

x kg – 10%.

x kg = 20 kg * 10%: 100% = 2 kg.

The dry matter mass is the same in grapes and raisins.

Then the share of dry matter in raisins is:

100% – 20% = 80%.

Let’s make the proportion:

x kg – 100%,

2 kg – 80%.

Let’s solve the proportion:

x kg = 2 kg * 100%: 80% = 2.5 kilograms.

Answer: the final mass of raisins is 2.5 kilograms.