Determine the probability that a for a seven-digit positive hexadecimal integer N, the sum of the first four digits of N is equal to the product of the last three digits of N.

(In reply to re(3): computer solution by Dej Mar)

What made my run time so long is going through all 7 digits' possibilities (about 1/4 billion) rather than reusing your a, b and c with d in going through 4 digits.

Posted by Charlie on 2014-12-25 20:55:51