There are $126$ cartons of apples. Each contains between $120$ and $144$ apples inclusive. At least $k$ cartons are guaranteed to contain the same number. Find the largest such $k$.
A small equilateral triangle is inscribed in a circle, which is inscribed in a larger equilateral triangle. Their areas are in the reduced ratio $m:n$. Find $m+n$.
Mark and Nick run in the same direction on a circular track of length $400$ m at $200$ and $160\text{ m/min}$ respectively. Starting together, after how many minutes do they meet again?