Also, barely any of my answers matched the actual answers, but they were close enough that I could pick from the multiple-choice. Apart from the algebra!
NO! NO NO NO NO NO! 3.56/7 ≈ 0.509. IT DOESN'T EQUAL ANY TERMINATING DECIMAL WHATSOEVER!
And Q4 is unsoluble as it stands because it never states that the angle at x and y is the centre of the circle, so the working can't justify the assumption that z = 0.5y.
This article is indicative of everything that's wrong with mathematics today. :-p