Assertion (A):
\( f(x) = \begin{cases} 3x - 8, & x \leq 5 \\ 2k, & x > 5 \end{cases} \)
is continuous at \( x = 5 \) for \( k = \frac{5}{2} \).
Reason (R):
For a function \( f \) to be continuous at \( x = a \),
\[ \lim_{x \to a^-} f(x) = \lim_{x \to a^+} f(x) = f(a) \]