Taking 2-2 Liters of Water
There are two bottles of 10 liters. Each bottle is completely filled with water.
Now 2 persons having empty bottles of 4 liters and 5 liters want to take 2-2 liters of water.
You can use only these 4 bottles (10 liter-full, 10 liter-full, 5 liter-empty, 4 liter-empty) to transfer the water.
How can this be done?
[Wasting or throwing of water is not permitted]