Did you solve it? A headful of PINs
by Alex Bellos from on (#639BW)
The solution to today's puzzle
Earlier today I set you this puzzle about PINs, the four-digit passcodes we use for phones and bank accounts.
In the comments, many people said that the answer was obvious. These people fell into the trap.
xx--
x-x-
x--x
-xx-
-x-x
--xx
Continue reading...