Two teachers, a warehouseman and a housewife make up tonight's group of aspirant ' Master-minds'. Whoever is to succeed requires supreme concentration, thorough subject specialisation and a wide general knowledge. A formidable task, but an exciting challenge. Contenders: JOHN TAYLOR, warehouseman - Northumbrian Kings of the sixth and seventh centuries MARGARET GARRATT, housewife, Dietetics JOHN BYERS , schoolmaster, Life and work of Evelyn Waugh NICHOLAS SPRUYTENBURG , teacher, Life and times of Edward II