Question

Assume that a DNA double helix contains 100 base airs one pair is A-T or C-G and there 45 cytosines how many guaninas are there? How many adeninas are there?

Answer 1

45 guanine, 55 adenines

Every cytosine needs a guanine to be a pair, so that is 45 pairs right there.
100-45 = 55
There should be 55 adenine and thymine pairs to fill in the remaining bases