Question 24
Alex writes down the value of the following sum, where the final term is the number consisting of 2020 consecutive nines:
$$9+99+999+9999+\cdots+\underbrace{99\ldots9}_{2019\text{ nines}}+\underbrace{99\ldots9}_{2020\text{ nines}}$$
How many times does the digit 1 appear in the answer?
$$9+99+999+9999+\cdots+\underbrace{99\ldots9}_{2019\text{ nines}}+\underbrace{99\ldots9}_{2020\text{ nines}}$$
How many times does the digit 1 appear in the answer?