If there were 10 bases of thymine in one strand of a DNA, there would also be 10 adenine bases in the complementary strand.
According to Chargaff's rule, the ratio of purine (adenine and guanine) to pyrimidine (thymine and cytosine) bases in DNAs is the same. Adenine always pairs with thymine while cytosine always pairs with guanine.
Thus, the number of thymine and adenine in a DNA must be equal. In the same vein, the number of guanine and cytosine must also be equal.
More on Chargaff's rule can be found here: https://brainly.com/question/19156457
