To know how many liters of water Bao use per liter of flour we have to divide the liters or flour so:

So Bao uses 0.33 or 1/3 of water per liter or flour
and to know hoy manu liters of flour Bao use per liter of water we have to made the oposite division so:

She use 3 liters of flour per liter of water