In Double Stranded DNA , Adenine pairs with Thymine as we know, it means amount of A = Amount of T. Here A=30% so T=30%
Total will be 100% (for all 4 bases) , left out is 30 % which will be equally divided by Guanine and Cytocine , hence G=20% and C=20%.
A=30% T=30% G=20% C=20%
