Ans: (a) $60$ marks (b) Yes
- Let $x$ marks be the score of David in the Mathematics examination.
$\begin{array}{rcl}
\dfrac{x-66}{12} & = & -0.5 \\
x – 66 & = & -6 \\
x & = & 60
\end{array}$Therefore, David get $60\text{ marks}$ in the Mathematics examination.
- The standard score of David in the Science examination
$\begin{array}{cl}
= & \dfrac{49 – 52}{10} \\
= & -0.3
\end{array}$Since the standard score of David in the Science examination is higher than that of David in the Mathematics examination, then the performance of David in the Science examination is better than in the Mathematics examination. Hence, the claim is correct.
