Sunday Times Teaser 2752 – Best Before

by Nick MacKinnon

published on 21st June 2015

A pandigital time is one where the minute, hour, day, month and year – each in two digit form – use all the digits 0 .. 9 among them.

For example 15:46 on 29/03/78 is a pandigital time.

(a) Since then, what was the latest pandigital time for which the product of its five component numbers is not divisible by a perfect square?

(b) What will be the first pandigital time for which the sum of its five component numbers is a perfect square?