First here is my disclaimer. I think this question is worded very poorly and the answer is ambiguous.

First you will need to know that 1mL=1cc (cubic centimter)

Now here is the first problem we don't know the third dimension of the bag or its true shape.

Assumption 1: It is a rectangular solid. If that is the case then its height can be found via the formula

Now here is problem number 2: The answer depends on which side is the bottom.

Again we use the volume formula but this time the volume of fluid 10mL.

Now we can pick two of the variables l,w, or h and plug them in to solve for the third. For example lets use l and w.

So now the water will cover the bottom and up to h on the 4 other sides and will not reach the top so the surface area is

If you repeat the above with l and h or h and w you will get two different answers!