Answer:
The answer to your question is: V = 2048 ml
Step-by-step explanation:
Data
Volume = 5000 ml
20% is evaporated per week
Volume of water left after 4 weeks = ?
Process
1st week 5000 ml ----------------- 100 %
x ----------------- 20 %
x = (20x 5000) / 100
x = 1000 ml
After a week there are = 5000 - 1000 = 4000 ml left
2nd week 4000 ml ---------------- 100 %
x ---------------- 20%
x = 800 ml
After two weeks, there are = 4000 - 800 = 3200 ml left
third weeks 3200 ml ----------------- 100 %
x ------------------ 20%
x = 640 ml
After three weeks there are 3200 - 640 = 2560 ml left
4rd 2560 ml ----------------- 100%
x ---------------- 20%
x = 512 ml
After four weeks there are 2560 - 512 = 2048 ml left
