experienced businessman training group in office

60s adult aged associates board briefing business businessman businesspeople casual caucasian cheerful colleagues color conference contact coworkers crew demo demonstrate demonstrating demonstration drawing education elderly european experienced expertise explaining eye face formal gray group hair happiness happy horizontal lecture lecturer lifestyle male man mature office old older people photo portrait present presentation presenting project room satisfied senior showing sixties skill smart smile smiling speaking staff standing stockphoto success successful teaching three training white whiteboard wise work working workplace