Answer:
If a scientist does an experiment where he puts 1/5 liters of water in 12 plants, and you want to see how much water he has put in all the plants together.
You would take 1/5 times 12
1/5*12=12/5
12/5 reduced would be 2 and 2/5 liters
2 and 2/5 liters of water in all plants
Hope this helps ;)