Can you use the switchboard to work out which 3-digit telephone extension number belongs to which member of staff?

Bill Cooper = 220

Harriet Wheeler = 102

Earnest Robinson = 312

Elizabeth Knight = 300

Richard November = 116

Stephen Cartwright = 428

Mary Hawkins = 508

Sam Cooper = 322

Simply follow the cables from the external lines (giving you the extension number) to the input bank, transfer the position of the plug on the input bank to the output bank and follow the next cable to the internal line to link the extension number to the name.