Tonight Mastermind enters its second decade and during the coming weeks 48 new contestants will be competing to win television's most prestigious quiz title. They come from every part of Britain, their ages range from 22 to 65 and their occupations include a naval officer, a tube train driver, a doctor, a brewery clerk, a bank manager and a vet. The first four contenders pit their wits against each other at the Royal Agricultural College, Cirencester. Geraldine Gregg-Smith, Education welfare officer - Novels of Evelyn Waugh Christopher Price, Civil servant - Novels of the Bronte Sisters Kathryn Tyson, Civil servant - Shakespeare's tragic heroes Diggory Seacome, Schoolmaster - Percussion playing from 1700