If the total amount of adenine and thymine in a double-stranded DNA is 45, what is the amount of adenine?

In a DNA segment, the amount of adenine (A) is equal to that of thymine (T) because they pair together. The total amount of adenine and thymine is given as 45. Therefore, we can set up the equation:

A + T = 45
Since A = T, we can substitute A for T:

A + A = 45
2A = 45
A = 45 / 2
A = 22.5
Therefore, the amount of adenine is 22.5