You still need to know the density of the 100% drug solution, without the density muliplied through you cannot get a measurement of mass. If they didn't give you the density, this problem is a hack

, and the work that you did is absolutely meaningless. the way you have to do it is: 3 mL (solution) * 1 mL (drug) / 100 mL (solution) * 200
from this you get 6 mL (drug) (I am assuming this is where you got 60, but I still don't see how that could have happened, unless the 1% solution was wrong, I guessed it wasn't the .01% as previously stated since you said it both ways I assumed you meant 1%)
But we still are stuck with mL of pure drug here, so we must have the density of the pure drug in order to get the mass. So the answer may be 60 mg if you looked it up or something, but you must do it the way shown above, and the density must be 10 mg / mL. To do it just by multiplying through and tacking on the mg unit is incorrect.
If the book this is from didn't give you the density and said the answer was 60 mg, throw it away, it was written by a half-retarded ape child.
Sorry for all this but incorrect units really get my panties in a bunch.
