Three identical capacitors are given a charge Q each and they are then allowed to discharge through resistance R₁, R₂ and R₃. Their charges, as a function of time shown in the graph below. The smallest of the three resistance is 

During the discharge of a capacitor through a resistance charge at any instant $\mathrm{Q}={\mathrm{Q}}_0{\mathrm{e}}^{\raisebox{1ex}{$-\mathrm{t}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{RC}$}\right.}$

$$\begin{gathered} \Rightarrow \frac{{\mathrm{Q}}_0}{\mathrm{Q}}={\mathrm{e}}^{\raisebox{1ex}{$\mathrm{t}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{RC}$}\right.} \\ \Rightarrow \mathrm{t}=\mathrm{CR} {\log }_{\mathrm{e}}\left(\frac{{\mathrm{Q}}_0}{\mathrm{Q}}\right) \end{gathered}$$

If Q → constant or same, then $\mathrm{t}\propto \mathrm{R}$

Now, draw a line parallel to the time axis as shown. Suppose this line cut the graphs at points 1, 2 and 3. Corresponding time are ${\mathrm{t}}_1,{\mathrm{t}}_2 \mathrm{and} {\mathrm{t}}_3$ respectively. Hence from graph t₁ < t₂ < t₃ ⇒ R₁ < R₂ < R₃