Meeting Name Cards I

4 people (ABCD) are at a table for a meeting. Sketch a way to place the name cards (abcd) such that they’re all mismatched.  Then rotate the table such that at least 2 people have the right name cards.

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Angles of Intersecting Chords

Here's a problem based on an obscure theorem about angles of intersecting chords.

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Factors of Non-Integers

Problem of the Week #93: Monday June 23rd, 2025As before, these problems are the results of me following my curiosity, and I make no promises regarding the topics, difficulty, solvability…

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Distance Sums

If we place 3 points on a line segment of length 1 and add up all pair-wise distances between them, what’s the biggest sum we can get?

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Centers at a Corner

Sketch the area reachable by the midpoint of a line segment of length 1, if its entire length is confined to the first quadrant (x>=0 and y>=0) of a Cartesian plane, and one of its end points must be on the x- or the y- axis.

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Pronic Fractions

A pronic number is a natural number of the form n(n+1), where n is also a natural number.  Let’s call the reciprocal of a pronic number a pronic fraction.

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Grid Colouring

How many ways are there to colour a 3x3 grid using 2 colours such that no rectangle in the grid has the same colour in all 4 corners? 

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Combined Chords

Two circles intersect at P and Q.  Let’s call line AB through P a combined chord if AP and PB are chords of the respective circles.  Let’s define the split product of AB as the length of AP times the length of PB.

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Linear Flooring

The floor function [a] denotes the greatest integer less than or equal to a.  For x and y strictly between 0 and 1, the probability of [2x]+[2y] being 1 is 1/2.

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Intersecting Circles

If we draw pairs of circles of the same sizes centered at two distinct points and mark where each pair of circles intersects, we’d trace out a straight line.

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