Project Euler — Problem 56 Solution


A googol (10100) is a mas­sive num­ber: one fol­lowed by one-hun­dred zeros; 100100 is almost unimag­in­ably large: one fol­lowed by two-hun­dred zeros. Despite their size, the sum of the dig­its in each num­ber is only 1.

Con­sid­er­ing nat­ur­al num­bers of the form, ab, where a, b < 100, what is the max­i­mum dig­i­tal sum?