Question

A single strand of DNA helix consists of 100 nitrogenous base pairs. On one strand, 36 of the bases are adenine and 24 are cytosine. For the complimentary strand of DNA, which would complete the proper base pairing?

Answer 1

The amount of Adenine always equals the amount of Thymine, and The amount of Cytosine always equals the amount of Guanine. (Chargaff's Rule)

So, Adenine is 36, therefore Thymine is 36.
Cytosine is 24, therefore Guanine is 24

That should add up to 100 base pairs if you add all 4 types together.