If the percentage of thymine is 30% what would the percentage of cytosine be

We use Chargaff's rule.[A] + [G] = [C] + [T][A] + [G] + [C] + [T] = 100%A is Adenine, G is Guanine, C is cytosine, T is Thymine.Adenine always pairs with Thymine.Guanine always  pairs with CytosineSo if Thymine is 30% then  Adenine is 30%  → 60% totalTherefore 100% - 60% = 40%40%  is shared equally among Cytosine and GuanineTherefore Cytosine will be 20% and Guanine 20%Cytosine is 20%