Question 25
What is the sum of the digits in the result of the subtraction
$$\underbrace{111\ldots111}_{20\text{ digits}}-\underbrace{222\ldots222}_{10\text{ digits}}$$
where the first number has 20 digits each 1, and the second has 10 digits, each 2?
$$\underbrace{111\ldots111}_{20\text{ digits}}-\underbrace{222\ldots222}_{10\text{ digits}}$$
where the first number has 20 digits each 1, and the second has 10 digits, each 2?