A DNA strand is 30% adenine. What percentage is guanine? (In DNA: A=T and G=C)
Answer
20 percent
How to solve it
1
Adenine: 30%, so Thymine: 30%
2
Remaining: 100% - 60% = 40%
3
Guanine = Cytosine: 40% ÷ 2 = 20%
Hints
A pairs with T (equal amounts)
G pairs with C (equal amounts)
All four must add to 100%