Maths Olympiad Prep

Library / /359 of 387

, 2005

Combinatorics Difficulty 3.0 AMC 10/12 Find the answer Canada

The non-negative difference between two numbers aa and bb is aba - b or bab - a, whichever is greater than or equal to 0. For example, the non-negative difference between 24 and 64 is 40. In the sequence 88,24,64,40,24,88, 24, 64, 40, 24, \ldots, each number after the second is obtained by finding the non-negative difference between the previous 2 numbers. The sum of the first 100 numbers in this sequence is

(A) 496496 (B) 760760 (C) 752752 (D) 776776 (E) 405405

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.