Question

DNA of a mouse was analyzed and found to be 35% adenine. What were the proportions of the remaining three nitrogen bases?

Answer 1

Adenine and thymine are always in the same quantity. So if there is 35% adenine, there is also 35% thymine. Combined, these make 70%. The remaining 30% is between the other two bases (guanine-cytosine), which are also in equal amounts. So, each of those has 15%.

To conclude:

Thymine, adenine 35% each

Guanine, cytosine 15% each