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