...and why would you state 3 greens in a training a/c?
3 greens relates to aircraft with retractable undercarriage, and the term is used as a confirmation that your landing gear is down and locked, and that you have 3 green lights on the instrument panel to confirm this. On all PPL single training stuff, like Cessna 150/152/172 / Piper PA28, etc, the undercarriage is fixed and not retractable, hence there are no '3 green' lights.