Ans: C
Let $x\text{ cm}$ be the mean height of the boys. Hence, we have
Let $x\text{ cm}$ be the mean height of the boys. Hence, we have
$\begin{array}{rcl}
\dfrac{54x + 36\times 153}{54+36} & = & 162 \\
54x + 5508 & = & 14580 \\
54x & = & 9072 \\
x & = & 168
\end{array}$
Therefore, the mean height of the boys is $168\text{ cm}$.
