$C = \dfrac{n}{V}$ is one fact wearing three outfits. Solved for the moles it reads $n = C \, V$ — how much solute a measured pour actually carries. Solved for the volume it reads $V = \dfrac{n}{C}$ — how much of a stock to draw when a recipe demands an exact mole count. Same relation, three exam questions.

And run the units through every rearrangement before you trust it: $\mathrm{mol/L} \times \mathrm{L}$ cancels to bare moles, so $n = CV$ survives the check. If the units refuse to cancel into the answer's units, the rearrangement is wrong — no appeal. Units that do work out never prove you right; the check is a one-way street, and it only ever runs against you.