All carp are fish all koi therefore is this valid and a sound argument?

The argument is valid, but not necessarily sound. Here's why:

* Valid: The argument follows a logical structure. It uses the syllogism form:

* All A are B (All carp are fish)

* All C are A (All koi are carp)

* Therefore, all C are B (Therefore, all koi are fish)

* Sound: A sound argument is valid AND its premises are true. In this case, the premises are true:

* All carp are fish: This is a true statement. Carp belong to the fish family.

* All koi are carp: This is also true. Koi are a specific type of carp.

Therefore, the argument is both valid and sound.