See Diminished for a lesson/tutorial about this test.
Do not attempt this exercise until you are proficient at naming the notes on the A, D, and G strings.
As always, you should practice this rubato (without a metronome) until you build up proficiency.
Set a metronome to 60 BPM. We will be playing half notes (two clicks per note).
Progress through every natural note in fourths.
Find the note as low on the neck as possible on the first three strings.
Form and strum the correct diminished triad inversion for the root note on that string.
Find the next location for that note higher up the neck (but still on the top three strings) and repeat with the next inversion.
Again, move up the neck and play the final inversion.
First you will strum all the B triads, then all the E triads, etc.
You can play all 36 triads in time and without mistakes.
Play around with individual notes from the triad in between the strummed chords. Try different rhythms (triplets, quarter/eighth/sixteenth notes, etc.) and articulations (sliding into chords or individual notes from a fret above or below, muting, louder/softer, vibrato, stacatto notes, etc.). Try to come up with musical sounding phrases.