Tonight I am talking about the psychology of sleep and dreams at the Edinburgh International Science Festival with Caroline Watt – details here. Hope you can make it. If you do come along, please say hi.
On Friday I set this puzzle….
Linda is the CEO of a big company. One day she walked out of her modestly sized boardroom and said to her secretary, ‘Here is a report about the company accounts for last year. I would like you to make a copy of this report for all of the board members, plus one copy for me and one copy for my mother’. Linda’s secretary, John, jumped up and ran to the photocopier. He returned exactly 11 minutes later, after photocopying 169 sheets of paper. How many board members are there?
If you have not tried to solve it, have a go now. For everyone else the answer is after the break.
169 can only be divided by 1, 13 and 169. Given that there must be more than 1 copy, and it is unlikely that there are over a hundred board members, John must have made 13 copies. One went to Linda, one to her mother, and thus there are 11 members of the board.
Did you solve it? Any other solutions?
I have produced an ebook containing 101 of the previous Friday Puzzles! It is called PUZZLED and is available for theKindle (UK here and USA here) and on the iBookstore (UK here in the USA here). You can try 101 of the puzzles for free here.