Library / /341 of 387

, 2008

Number theory Difficulty 3.0 AMC 10/12 Find the answer Canada

Suppose $N = 1 + 11 + 101 + 1001 + 10001 + \ldots + 1\underbrace{000\ldots00}_{50 \text{ zeroes}}1$ . When $N$ is calculated and written as a single integer, the sum of its digits is

(A) $50$ (B) $99$ (C) $55$ (D) $58$ (E) $103$

Want a route through all this instead of an archive? The track puts 2,604 problems in a working order, from Junior Challenge level to the IMO shortlist.

Source: CEMC, University of Waterloo, licensed CC-BY-NC-4.0. Statement reproduced verbatim; metadata (topic, difficulty) added by this project. Solutions are the publisher's, linked not copied.