Not that great at maths so bear with me.
To find out how many containers she used: 30/10 = 3 So 3x3 is 9 then x by two to find out how much water : 9x2=18
Water vapor releases energy by through evaporation. None of your options are correct, buddy.
A) 8% - because cytosine pairs with guanine so they have the same percentage and that makes it up to 84%. Adenine and Guanine also occur in the same percentages are they pair so 100-84 leaves 16% remaining, divided by 2 leaves 8% for both cytosine and guanine.