2 IS THE ONLY EVEN PRIME NUMBER a prime number can only be divided by 1 or itself. 4 is a composite and 5 is a prime hope this helps you.
No. of gallons required = csa of cuboid+area of rectangle/300
= 2(l+b)h + l*b /300
= 2(11+12)8 +11 *12 /300
=368+132/300
= 500/300
=5/3 =1.666.... =1.7
= 2 approx.
therefore 2 gallons should be used
I think it’s 1.8 because if you divide it and you get your answer if you were saying what goes in it