olymmath

CL-MO 2022

Chile national mathematics olympiad 2022.

Other problems

Problem 2

Let ABCABC be a triangle such that ∠CAB=60o\angle CAB = 60^o . Consider D,ED, E points on sides ACAC and ABAB respectively such that BDBD bisects angle ∠ABC\angle ABC , CECE bisects angle ∠BCA\angle BCA and let II be the intersection of them. Prove that ∣ID∣=∣IE∣|ID| =|IE| .

Problem 3

The 1919 numbers 472472 , 473473 , ...... , 490490 are juxtaposed in some order to form a 5757 -digit number. Can any of the numbers thus obtained be prime?