Susan couldn't quite remember her bank PIN code.
She knew:

It had 4 or 5 digits.

It used 4 or 5 different digits.

The first digit is 4 or 5.

The second digit is 4 or 5 and none of the other digits is smaller.

The number is 4 or 5 times a prime number.

If you reverse the order of the digits, the resulting number has 4 or 5 prime factors, all different.

In 4 or 5 of these facts, the "4" is the correct number.
What is Susan's PIN code?
(In reply to
Possible solution by broll)
Your number does not work. 54476
5 digits
4 different digits
5 for 1st digit
4 for 2nd digit none smaller
4 times the prime 13619
4 factors of its reversal: 67445 = 5*7*41*47
The last bullet cannot be fulfilled. If we put 4 there are 5 4s, if we put 5 there are only 4.

Posted by Jer
on 20101119 16:13:10 