Out of the two metals $P$ and $Q$, $P$ is less reactive than $Q$. Suggest an activity to arrange these metals in the order of their decreasing reactivity. Support your answer with a suitable chemical equation.

(N/A) Activity: Take a small amount of the salt solution of metal $P$ in a test tube and add metal $Q$ to it. Since metal $Q$ is more reactive than metal $P$, it will displace metal $P$ from its salt solution.
Chemical equation:
Metal $Q + \text{Salt solution of } P \rightarrow \text{Salt solution of } Q + \text{Metal } P$