A sequence of DNA has 300 nitrogenous base pairs, of which 75 are Guanine. What is the number of Thymine in this sequence ?

75

Reason

If Guanine = 75, then cytosine = 75
So, Guanine + Cytosine = 75 + 75 = 150

Remaining bases = 300 - 150 = 150

Adenine + Thymine = 150

Since, Adenine = Thymine
So, we will divide 150 equally between them.

150/2 = 75

So, Adenine = Thymine = 75