OMK 2016 Bongsu Problem B2 Solution

A student managed to recall problem B2 (Bahagian B, No. 2) of the Malaysian National Mathematical Olympiad (Olimpiad Matematik Kebangsaan, OMK) 2016 Bongsu category whose question & solution are in the images below:

*I don’t have the other questions with me since it’s a closed paper.