In an examination in which full marks were 800, A gets 20\% more than B, B gets 20\% more than C, and C gets 15\% less than D. If A got 576, what percentage of full marks did D get (approximately)?
(a)45.7
(b)51.2
(c)58.8
(d)61.7
Answer
Answer (as printed): C
Explanation
$A=\frac{120}{100} B, B=\frac{120}{100} C$ and $C=\frac{85}{100} D$. $$\begin{aligned} & \therefore \quad B=\frac{5}{6} A, C=\frac{5}{6} B \text { and } D=\frac{20}{17} C . \\ & B=\frac{5}{6} \times 576=480 ; C=\frac{5}{6} \times 480=400 ; D=\frac{20}{17} \times 400=\frac{8000}{17} . \end{aligned}$$
Explanation as extracted from the printed page; notation may be imperfect.