I need help solving this riddle...

You have 3 cars and 1 tank of water, 1 tank of oil, and 1 tank of gas...

So lets draw it out

C C C

W O G


Question is... How do you get each car gas, oil and water without crossing any lines. You have you draw 3 lines going from each car to each of the tanks... I haven't figured this out in tweleve years...

Here's a similar riddle, using three houses and three utilities... sounds like it is an unsolveable riddle unless you use a 'trick' - pass one of the items through one of the cars to another, but that's kind of cheating.. this link explains how it can be solved, the explanation is kind of out of my league.. hope it makes sense to you!
Math Forum: Ask Dr. Math FAQ: Three Houses, Three Utilities