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Chances for a business meeting

Jack will enter the office today at a random time between 2pm and 3pm. He will stay in the office for 15 minutes. John has a similar schedule, with the entry time chosen independently.

They have a business to transact and it requires that they are together in the office for 5 minutes before 3pm. What are the chances that the business is transacted today?

WIN £15 will be awarded to the sender of the first correct answer opened on Wednesday 22 December 2010. The Editor’s decision is final. Please send entries to Enigma 1622, New ÐÓ°ÉÔ­´´, Lacon House, 84 Theobald’s Road, London WC1X 8NS, or to enigma@newscientist.com (please include your postal address).

Answer to 1616 One good turn: Penny turned over a counter 33 times

The winner Tony McCoy O’Grady of Rathfarnham, Dublin, Ireland