This is a Pascal Contest Question, specifically, question 16 from the year 2021. It is a grade 9 math contest offered by the University of Waterloo. Try and solve it. Be sure to subscribe so you don't miss out on more practice questions. If you plan on writing the Contest this year, good luck! Check out my channel for questions from math contests for high school students from the other grades in high school and from the SIN High School Physics Contest. Also, see my website for free high school math and science resources: youtubephysicsteacher.ca