Consider the following Assertion (A):
\[
5^{2n}-3^{2n-1}
\]
is divisible by 2 for all \(n\in\mathbb N\).
Reason (R):
\[
5^{2n}+3^{2n-1}
\]
is divisible by 7 for all \(n\in\mathbb N\).
Show Hint
For Assertion--Reason questions involving divisibility, always test the reason using the smallest possible values such as \(n=1\) or \(n=2\). A single counterexample is enough to disprove a universal statement.