Answer

The correct choice:

100 kg.

First, let's calculate the composition of the vegetables when you first picked them. They had 99% water in them. That means they had 198 pounds of water and 2 pounds of fiber. That fiber was 1% in the morning:

100% — 99% = 1%.

By the condition of the problem, these 2 kilograms of fiber cannot evaporate or disappear, because the weight is always the same. Only water evaporates.

Now count the composition of the vegetables in the evening: the water was already 98%. This means that the amount of water has decreased, but all the fiber has remained in place. But the percentage of fiber to water has changed: now the same 2 kilograms of fiber takes up 2% of the total weight. Let's calculate how much all the tomatoes weigh in the evening then:

2% of the vegetables weigh 2 kilograms, which means 20% weigh 20 kilograms.

Let's multiply both parts by 5 to get the total weight. We get:

100% = 100 kg.

The answer is 100 kilograms.