by Graham Smithers
Published November 11 2018 (link)
Using all but one of the digits 0 to 9, and systematically replacing them by a letter, my pin numbers become ONE, TWO, FIVE and SEVEN.
These numbers are such that:
ONE is odd
TWO is even
FIVE is odd and divisible by 5
SEVEN is divisible by 7
ONE + TWO + TWO = FIVE
If I told you which digit was not used, you should be able to work out my pin numbers.
What pin number is represented by SEVEN?