.Hmmm.. Paradox's Logic sounds good now!!.. Ok Just for Paradox's sake!! -->30 litre Oil + 30 litre Water - 11*2 litre Oil = 8 litre Oil + 30 litre water -->8 litre Oil + 30 litre water+ 7*2 litre Oil = 22 litre Oil + 30 litre water -->22 litre Oil + 30 litre water- 11*2 litre Oil = 30 litre water Voila!! Innit, Paradox??...:)