Oil tanker problem needing area when thickness of oil is given

Oil tanker carrying 2.0 X10^5 metric tons of crude oil of density .70g/cm^3 breaks up at sea, what area of ocean in km^2 will be polluted if the oil spreads out to the thickness of .10 mm?? Metric ton = 1000 kg.

Ans is 2900 km^2.

So change the metric ton to kg is 2x10^8 kg.

Now kinda stuck again. I hae no clue what it is asking and what formula to use again.

HELP PLEASE. again, this is our own study material that we need to work out, nothing to hand in and need this to study from.

Please help thanks

Joannehttp://www.chemistryhelpforum.com/ch...milies/eek.gif

I DON"T KNOW WHERE TO START.(Headbang)