Hello all, I have 3 bottles of juice, 2 almost empty. They are all the same Menthol flavor from the same vendor and I would like to combine them. They are different strengths, as follows; 30ml of 15mg, 8ml of 18mg and 4ml of 24mg. If I combine all 3 of them, what will be the final mg strength of the 42ml ? Any help greatly appreciated. Thank you hfm