$v = d/t$ is one fact wearing three outfits: solve it for $v$, for $d$, or for $t$, and it answers three different exam questions. The rearranging is the physics — the arithmetic afterward is just bookkeeping. From here on, every question can ask for ANY of the three, so the ladder is: pick the formula, rearrange it for what you want, put the numbers in their sockets, and only then compute.

And run the free check before any arithmetic: push the units through your rearrangement. $d/t$ is metres over seconds — $\mathrm{m/s}$, a speed — so $v = d/t$ survives. If the units refuse to cancel into the units your answer needs, the rearrangement is wrong. Full stop, no appeal. But mind the one-way street: units guide the way, they can’t be relied on completely. Wrong units always prove a wrong rearrangement; right units never prove a right one.