Experiment of December 6, 2025:

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Solution video:

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Experiment:

Question:

What is the maximum number of coins she can place in both attempts?

A) First attempt: 24 coins, second attempt: 24 coins.

B) First attempt: 25 coins, second attempt: 25 coins.

C) First attempt: 24 coins, second attempt: 25 coins.

D) First attempt: 25 coins, second attempt: 24 coins.

Advice of the day:

The coins may protrude a few millimetres beyond the edge of the rectangle, especially vertically. Only options for 24 or 25 coins are required, no mm-sizes about the dimensions of the rectangle.