40 - x^2 = 0
x^2 = 40
x = + 40^0.5 or x = - 40^0.5
Quickly using a calculator (or long division) reveals that 191/238=<span>0.8025=80.25%, which is close to 80%=4/5
Similarly, 106/160=0.6625=66.25%, which is close to 66.67%=2/3</span>
Andrew answered 34 questions correctly.
I got the answer by divided the 85% by 100% (100% because it's the total percentage.) I received 0.85 when dividing that. Then, I took the 0.85 and divided it by the total of 40 questions, and that gave me the answer of 34.
The answer is A because when you add the angles to get they equal 180. Then just solve for x.
The drawing isn't to scale