You have three bowls with you of capacity 8, 5 and 3 liters. The 8 liters bowl is filled completely. Using these three bowls you have to divide the 8 liters in (4 + 4) liters. How can you do it in minimum number of transfers?

Water Gallon Riddle

Fill the 5 liters bowl from the 8 liters bowl.
Take the 5 liters bowl and fill the 3 liters bowl.
Take this 3 liters bowl and empty it inside 8 liters bowl.
Pour the remaining 2 liters from the 5 liters bowl to the 3 liters bowl.
Take the 8 liters bowl and pour it in the 5 liters bowl.
Pour the missing 1 liter from the 5 liter bowl to the 3 liters bowl.
Now there is 4 liters left in the 5 liters bowl.
Now pour 3 liters back from the 3 liters bowl to the 8 liters bowl.

That's it, we now have 4 liters in the 8 liters bowl and 5 liters bowl.