Aswimming pool had 2.5, point, 5 million liters of water in it. some water evaporated, and then the pool only had 2 million liters of water in it. what percent of the water evaporated?

The percent of water evaporated would be:

percent of water evaporated: evaporated water/ original swimming pool volume * 100%
0.5 million liters / 2.5 million liters * 100%= 
1/5 *100%= 20%
-adriansp