Let be the number formed by digits equal to , that is, .
Compute the sum of the digits of the number .
Solution
Given a number consisting of 2022 digits, all equal to 1, we aim to compute the sum of the digits of the number .
### Step 1: Express Numerically
The number can be expressed numerically as a sequence of ones, mathematically expressed as:
### Step 2: Calculate
Multiply by 9, which simplifies the form:
This is a number consisting of 2022 nines.
### Step 3: Calculate
To find , express using the expression for :
Now, add to this expression:
Thus, we have that:
As seen above, both terms simplify upon combining:
### Step 4: Sum the Digits of the Result
The number represents a number with a 1 at the first, a 1 at the 2023rd place, followed by zeros, and a trailing -1, producing all 9s thereafter until the last digit is 1.
For calculation, it produces a number of digits summing to:
Hence, the sum of the digits of is: