In Russia you get into a bus, take a ticket, and sometimes say : Wow, a lucky number! Bus tickets are numbered by 6-digit numbers, and a lucky ticket has the sum of 3 first digits being equal to the sum of 3 last digits. When we were in high school (guys from math school No. 7 might remember that ) we had to write a code that prints out all the lucky tickets' numbers; at least I did, to show my loyalty to the progammers' clan. Now, if you add up all the lucky tickets' numbers you will find out that 13 (the most unlucky number) is a divisor of the result. Can you prove it (without writing a code)?
Subscribe to:
Post Comments (Atom)
Echo , the dolphin
Echo, a dolphin is trying to jump through a circular hole in his enclosure to escape from the aquarium. From echo's perspective just u...
-
Circle in a chess board Consider an infinite chessboard, where the squares have side length of 1. The squares are colored black and whit...
-
A inch diameter round pizza has been sliced by straight cuts, leaving a right triangle in the middle as shown here The edge of the...
-
100 Gold Coins Five pirates have obtained 100 gold coins and have to divide up the loot. The pirates are all...
No comments:
Post a Comment