Problem 56

Problem 56

Powerful Digit Sum

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?



若a, b < 100,所有能表示为ab的自然数中,最大的各位数字和是多少?