Question 19
What are the last three digits of the sum
$$1+11+111+\cdots+\underbrace{111\ldots111}_{70\text{ digits}}?$$
$$1+11+111+\cdots+\underbrace{111\ldots111}_{70\text{ digits}}?$$
SASMO 2014 Primary 4 (Grade 4) Contest Question 19
SASMO · SASMO 2014 Primary 4 (Grade 4) Contest