Question

If a sample of DNA is 34% guanine what percentage of the sample will be thymine?

Answer 1

It is a 1:1 ratio with G and C, same as A and T.
If G is 34% than C would be 34% as well. adding those two would give you 68% you would subtract that from 100% which would be 32%. Divide that by 2 and you get 16% each for A and T.
A= 16%, T= 16%, G= 34%, and C= 34%

Answer 2

Thymine and adenine pair up. Guanine and cytosine pair up. This means that Guanine and Cytosine must have an equal amount and Thymine and Adenine must have an equal amount. If 34% is Guanine, then 34% is also Cytosine. Add those up and G-C makes up 68% of the DNA, meaning that 32% is left for the Thymine and Adenine pairing. Divide 32 by 2 to get 16% of Thymine.