Explanation:
-You know that the complete DNA is 100% and that from that total 37% is guanine.
-With that information you can deduce that 37% is cytosine (remember what we talked about above about G-C base complementarity).
-That means that 74% is occupied by those two bases C and G (37+37=74) and therefore 26% is left for the rest of the bases.
-The bases left are T and A, as they are complementary to each other what remains to do is divide that 26% in two.
Answer:
-13 is the percentage of thymine bases.