Is dividing displacement by velocity to figure out time valid since they are both vectors?

Hi Guys,

I am recently learning the Position, acceleration, and velocity part of the AP Physics 1. The worked example of solving for time really confuses me. The formula v=st makes sense to me. However, is the other way around t=v/s valid? The point is that velocity and displacement are both vector quantities and the quotient of two vector quantities is not well defined.

Is this acceptable? If not, should I specify that since they are pointing to the same direction, they can be "converted" into scalers like speed and distance and then used to calculate the time? If anyone could help me with this, I would greatly appreciate it. Thank you!