In this 'Jubilee' year, the Mastermind series celebrates its centenary with the 100th programme coinciding with this year's Final. To reach the Final, 48 contenders, selected from the many thousands of applicants throughout the United Kingdom, line up for the first-round heats of this intellectual marathon. The arena for tonight's confrontation is Reading University. The contenders are: HUGH MERRICK author and translator - The Alps MARTIN LEADBETTER, fingerprint expert - Instruments of the Symphony Orchestra SUE JENKINS, student teacher - Children's literature IAN SEWELL, printer - Old Testament