Just who were Maggie Thatcher's childhood friends? Put on your thinking caps. This weekend is the 18th annual Midwest Trivia Contest at Lawrence University in Appleton, Wis.
The campus radio station will broadcast such stumpers as which Broadway play was advertised on the side of the bus that drove by after Dustin Hoffman's first day on the job in ''Tootsie.'' Or, who were the two girls on either side of British Prime Minister Margaret Thatcher in her 1934 Huntingtower Road Primary School graduation picture?
Many of the teams, which include local residents, have installed extra telephones for this taxing effort. Prizes will range from pink plastic flamingos to mouse traps.
For trivia buffs, the answers to the above puzzlers: ''Evita'' and Barbara Bools and Kathleen Howard.