Library / /350 of 387

, 2005

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

If $x$ is a positive integer less than 100, how many values of $x$ make $\sqrt{1 + 2 + 3 + 4 + x}$ an integer?

(A) $6$ (B) $7$ (C) $8$ (D) $9$ (E) $10$

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.