Skip to content

Sunday Times Teaser 2684 – How Safe?

by Robin Nayler

The combination of a lock with six different digits is formed by concatenating three two-digit primes.

The sum and the product of its six digits are both perfect squares and the combination is a multiple of the difference between this sum and this product.

What is the combination?

2 Comments Leave one →
  1. brian gladman permalink

    This is easy with a computer but is a bit more interesting on paper.

  2. tonysmith permalink

    It is also easy on paper – but not so easy to prove there is no solution if repeated digits are allowed.

Leave a Reply

Note: HTML is allowed. Your email address will not be published.

Subscribe to this comment feed via RSS